Front end systems and related devices, integrated circuits, modules, and methods

ABSTRACT

Front end systems and related devices, integrated circuits, modules, and methods are disclosed. One such front end system includes a low noise amplifier in a receive path and a multi-mode power amplifier circuit in a transmit path. The low noise amplifier includes a first inductor, an amplification circuit, and a second inductor magnetically coupled to the first inductor to provide negative feedback to linearize the low noise amplifier. The multi-mode power amplifier circuit includes a stacked output stage including a transistor stack of two or more transistors. The multi-mode power amplifier circuit also includes a bias circuit configured to control a bias of at least one transistor of the transistor stack based on a mode of the multi-mode power amplifier circuit. Other embodiments of front end systems are disclosed, along with related devices, integrated circuits, modules, methods, and components thereof.

CROSS-REFERENCE TO PRIORITY APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119(e)of U.S. Provisional Patent Application No. 62/440,241, titled FRONT ENDSYSTEMS, filed Dec. 29, 2016; U.S. Provisional Patent Application No.62/480,002, titled FRONT END SYSTEMS AND RELATED DEVICES, INTEGRATEDCIRCUITS, MODULES, AND METHODS, filed Mar. 31, 2017; U.S. ProvisionalPatent Application No. 62/570,549, titled FRONT END SYSTEMS AND RELATEDDEVICES, INTEGRATED CIRCUITS, MODULES, AND METHODS, filed Oct. 10, 2017;U.S. Provisional Patent Application No. 62/571,409, titled FRONT ENDSYSTEMS AND RELATED DEVICES, INTEGRATED CIRCUITS, MODULES, AND METHODS,filed Oct. 12, 2017; U.S. Provisional Patent Application No. 62/594,179,titled FRONT END SYSTEMS AND RELATED DEVICES, INTEGRATED CIRCUITS,MODULES, AND METHODS, filed Dec. 4, 2017; and U.S. Provisional PatentApplication No. 62/595,935, titled FRONT END SYSTEMS AND RELATEDDEVICES, INTEGRATED CIRCUITS, MODULES, AND METHODS, filed Dec. 7, 2017.The disclosures of each of these priority applications are herebyincorporated by reference in their entireties herein.

BACKGROUND Technical Field

Embodiments of this disclosure relate to radio frequency electronicsystems, such as front end systems and related devices, integratedcircuits, modules, and methods.

Description of Related Technology

A radio frequency electronic system can process radio frequency signalsin a frequency range from about 30 kilohertz (kHz) to 300 gigahertz(GHz), such as in a range from about 450 megahertz (MHz) to 6 GHz. Afront end system is an example of a radio frequency electronic system. Afront end system can be referred to as a radio frequency front endsystem. A front end system can process signals being transmitted and/orreceived via one or more antennas. For example, a front end system caninclude one or more switches, one or more filters, one or more low noiseamplifiers, one or more power amplifiers, other circuitry, or anysuitable combination thereof in one or more signal paths between one ormore antennas and a transceiver. Front end systems can include one ormore receive paths and one or more transmit paths.

A front end system can include a low noise amplifier (LNA) in a receivepath. The LNA can receive a radio frequency (RF) signal from an antenna.The LNA can be used to boost the amplitude of a relatively weak RFsignal. Thereafter, the boosted RF signal can be used for a variety ofpurposes, including, for example, driving a switch, a mixer, and/or afilter in an RF system. LNAs can be included in a variety ofapplications, such as base stations or mobile devices, to amplifysignals of a relatively wide range of radio frequency signals.

A front end system can include a power amplifier in a transmit path.Power amplifiers can be included in front end systems in a wide varietyof communications devices to amplify an RF signal for transmission. AnRF signal amplified by a power amplifier can be transmitted via anantenna. Example communications devices having power amplifiers include,but are not limited to, mobile phones, tablets, base stations, networkaccess points, laptops, computers, and televisions. As an example, inmobile phones that communicate using a cellular standard, a wirelesslocal area network (WLAN) standard, and/or any other suitablecommunication standard, a power amplifier can be used to amplify the RFsignal.

Electrical overstress (EOS) events can occur in a front end system. EOSevents can arise from a variety of sources, such as external chargesources, supply switching, and/or electromagnetic pulses. EOS eventsinclude electrostatic discharge (ESD) events and other transientelectrical events associated with relatively high levels of power and/orcharge. An EOS event can cause charge build-up in an integrated circuit(IC), leading to high voltage and/or current levels beyond which the ICcan reliably tolerate. Absent a protection mechanism, the EOS event canlead to IC damage, such as gate oxide rupture, junction breakdown,and/or metal damage. An IC's robustness to EOS events can be evaluatedin a wide variety of ways. For example, specifications for EOScompliance can be set by various organizations, such as theInternational Electrotechnical Commission (IEC) and/or Joint ElectronicDevice Engineering Council (JEDEC). For instance, a human body model(HBM) test can be used to evaluate the IC's performance with respect toESD events arising from the sudden release of electrostatic charge froma person to an IC. An IC's performance with respect to suchspecifications can be a significant performance metric by which the ICis evaluated.

Some or all of a front end system can be embodied in packagedsemiconductor module. Packaged semiconductor modules can includeintegrated shielding technology within a package. A shielding structurecan be formed around a radio frequency component of a front end system.The shielding structure can shield the radio frequency component fromelectromagnetic radiation that is external to the shielding structure.The shielding structure can shield circuit elements external to theshielding structure from electromagnetic radiation emitted by the radiofrequency component. As more components are being integrated togetherwith each other in a radio frequency module, shielding components fromeach other in a compact and efficient manner can be challenging.

A system in a package (SiP) can include integrated circuits and/ordiscrete components within a common package. Some or all of a front endsystem can be implemented in a SiP. An example SiP can include asystem-on-a-chip (SoC), a crystal for clocking purposes, and a front-endmodule (FEM) that includes a front end system. In certain SiPs, a SoCand a crystal can consume a relatively large amount of physical area.This can create a relatively large footprint for the SiP.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

The innovations described in the claims each have several features, nosingle one of which is solely responsible for its desirable attributes.Without limiting the scope of the claims, some prominent features ofthis disclosure will now be briefly described.

One aspect of this disclosure is a packaged module that includes a lownoise amplifier within a package and a multi-mode power amplifiercircuit within the package. The low noise amplifier includes a firstinductor, an amplification circuit, and a second inductor magneticallycoupled to the first inductor to provide negative feedback to linearizethe low noise amplifier. The multi-mode power amplifier circuit includesa stacked output stage including a transistor stack of two or moretransistors. The multi-mode power amplifier circuit also includes a biascircuit configured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifiercircuit.

The packaged module can further include a package substrate, a radiofrequency shielding structure extending above the package substrate andenclosing the low noise amplifier and the multi-mode power amplifiercircuit, and an antenna on the package substrate external to the radiofrequency shielding structure. The antenna can be a multi-layer antenna.The packaged module can include a die supported by a package substrateand a crystal supported by the package substrate, in which the crystalis disposed between the die and the package substrate, and in which thedie includes the low noise amplifier and the multi-mode power amplifier.

Another aspect of this disclosure is a front end system that includes alow noise amplifier in a receive path of the front end system and amulti-mode power amplifier circuit in a transmit path of the front endsystem. The low noise amplifier includes a first inductor, anamplification circuit, and a second inductor magnetically coupled to thefirst inductor to provide negative feedback to linearize the low noiseamplifier. The multi-mode power amplifier circuit includes a stackedoutput stage including a transistor stack of two or more transistors.The multi-mode power amplifier circuit also includes a bias circuitconfigured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifiercircuit.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The amplification circuit can be configured to receive a radio frequencysignal by way of the first inductor. The low noise amplifier can includean input matching circuit including the first inductor. The inputmatching circuit can further include a series inductor having a firstend configured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The matching circuit caninclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor. The matching circuit caninclude a shunt capacitor electrically coupled to the first end of theseries inductor. The first inductor and the second inductor can togetherfunction as a transformer having a primary winding in series with aninput of the amplification circuit and a secondary winding connectedbetween a transistor of the amplification circuit and a low voltagereference.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can include a cascode transistor in series with the commonsource amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can include a cascode transistor in series withthe common emitter amplifier.

The front end system can include a radio frequency switch coupled to thelow noise amplifier and the multi-mode power amplifier circuit. Theradio frequency switch can be configured to electrically couple anantenna port to the transmit path in a first state and to electricallycouple the antenna port to the receive path in a second state.

A wireless communication device can include the front end system. Asingle integrated circuit can include the front end system. The singleintegrated circuit can be a semiconductor-on-insulator die. The frontend system can be embodied in a packaged module.

Another aspect of this disclosure is a front end system that includes alow noise amplifier in a receive path of the front end system and apower amplifier in a transmit path of the front end system. The lownoise amplifier includes a first inductor, an amplification circuit, anda second inductor magnetically coupled to the first inductor to providenegative feedback to linearize the low noise amplifier. The poweramplifier includes an injection-locked oscillator driver stage.

The amplification circuit can receive a radio frequency signal by way ofthe first inductor. The low noise amplifier can include an inputmatching circuit that includes the first inductor. The input matchingcircuit can further include a series inductor having a first endconfigured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The input matching circuitcan further include a shunt capacitor electrically coupled to the firstend of the series inductor. The input matching circuit can furtherinclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can further include a cascode transistor in series with thecommon source amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can further include a cascode transistor in serieswith the common emitter amplifier.

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

The front end system can further include a radio frequency switchcoupled to the low noise amplifier and the power amplifier. The radiofrequency switch can be configured to electrically couple an antennaport to the transmit path in a first state and to electrically couplethe antenna port to the receive path in a second state.

A wireless communication device can include the front end system. Asingle integrated circuit can include the front end system. The singleintegrated circuit can be a semiconductor-on-insulator die. The frontend system can be embodied in a packaged module.

Another aspect of this disclosure is a front end integrated circuit thatincludes a low noise amplifier including a first inductor, anamplification circuit, and a second inductor magnetically coupled to thefirst inductor to provide negative feedback to linearize the low noiseamplifier, the low noise amplifier being controllable by a controlsignal; an input pad configured to receive the control signal; and anoverstress protection circuit including an overstress sensing circuitelectrically connected between the input pad and a first supply node, animpedance element electrically connected between the input pad and asignal node, and a controllable clamp electrically connected between thesignal node and the first supply node, the overstress sensing circuitconfigured to activate the controllable clamp in response to detectingan electrical overstress event at the input pad.

The amplification circuit can receive a radio frequency signal by way ofthe first inductor. The low noise amplifier can include an inputmatching circuit that includes the first inductor. The input matchingcircuit can further include a series inductor having a first endconfigured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The input matching circuitcan further include a shunt capacitor electrically coupled to the firstend of the series inductor. The input matching circuit can furtherinclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can further include a cascode transistor in series with thecommon source amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can further include a cascode transistor in serieswith the common emitter amplifier.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

A wireless communication device can include the front end integratedcircuit. A packaged module can include the front end integrated circuit.The front end integrated circuit can be embodied on asemiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a radio frequency shielding structure extending abovethe package substrate, a front end integrated circuit positioned in aninterior of the radio frequency shielding structure, and an antenna onthe package substrate external to the radio frequency shieldingstructure. The front end integrated circuit includes a low noiseamplifier that includes a first inductor, an amplification circuit, anda second inductor magnetically coupled to the first inductor to providenegative feedback to linearize the low noise amplifier.

The radio frequency shielding structure can include a plurality of wirebonds disposed between the antenna and the front end integrated circuit.The radio frequency shielding structure can include wire bond wallsdisposed around at least two sides of the front end integrated circuit.The radio frequency shielding structure can include a shielding layersubstantially parallel to the package substrate, and the front endintegrated circuit can be disposed between the shielding layer and thepackage substrate. The shielding layer can include copper. The packagedmodule can further include a protective layer over the shielding layersuch that the shielding layer is disposed between the protective layerand the front end integrated circuit. The protective layer can includetitanium.

The antenna can be a multi-layer antenna. A first portion of the antennacan be on a first side of the package substrate and a second portion ofthe antenna can be on a second side of the package substrate, in whichthe second side opposes the first side.

The amplification circuit can receive a radio frequency signal by way ofthe first inductor. The low noise amplifier can include an inputmatching circuit that includes the first inductor. The input matchingcircuit can further include a series inductor having a first endconfigured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The input matching circuitcan further include a shunt capacitor electrically coupled to the firstend of the series inductor. The input matching circuit can furtherinclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can further include a cascode transistor in series with thecommon source amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can further include a cascode transistor in serieswith the common emitter amplifier.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The low noise amplifiercan be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes amulti-layer substrate including a ground plane, an antenna on a firstside of the multi-layer substrate, and a front end integrated circuit ona second side of the multi-layer substrate. The front end integratedcircuit includes a low noise amplifier that includes a first inductor,an amplification circuit, and a second inductor magnetically coupled tothe first inductor to provide negative feedback to linearize the lownoise amplifier. The ground plane is positioned between the antenna andthe front end integrated circuit.

The amplification circuit can receive a radio frequency signal by way ofthe first inductor. The low noise amplifier can include an inputmatching circuit that includes the first inductor. The input matchingcircuit can further include a series inductor having a first endconfigured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The input matching circuitcan further include a shunt capacitor electrically coupled to the firstend of the series inductor. The input matching circuit can furtherinclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can further include a cascode transistor in series with thecommon source amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can further include a cascode transistor in serieswith the common emitter amplifier.

The packaged module can include conductive features disposed around thefront end integrated circuit and electrically connected to the groundplane, the conductive features and the ground plane can be operable toprovide shielding to the front end integrated circuit. The conductivefeatures can include solder bumps. The packaged module can include amolding material around the front end integrated circuit, and a viaextending through the molding material to electrically connect theground plane and a solder bump of the solder bumps. The antenna can be afolded quarter wave antenna. The antenna can be a loop antenna.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal supported by the package substrate, and a secondintegrated circuit supported by the package substrate. The firstintegrated circuit is disposed between the crystal and the packagesubstrate. The second integrated circuit includes a low noise amplifierthat includes a first inductor, an amplification circuit, and a secondinductor magnetically coupled to the first inductor to provide negativefeedback to linearize the low noise amplifier.

The amplification circuit can receive a radio frequency signal by way ofthe first inductor. The low noise amplifier can include an inputmatching circuit that includes the first inductor. The input matchingcircuit can further include a series inductor having a first endconfigured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The input matching circuitcan further include a shunt capacitor electrically coupled to the firstend of the series inductor. The input matching circuit can furtherinclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can further include a cascode transistor in series with thecommon source amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can further include a cascode transistor in serieswith the common emitter amplifier.

The crystal, the first integrated circuit, and the second integratedcircuit can be disposed on a first side of the package substrate. Thecrystal and the first integrated circuit can be disposed on a first sideof the package substrate, and the second integrated circuit can bedisposed on a second side of the package substrate opposite the firstside. The first integrated circuit can include a microprocessor and atleast one of radio frequency transmitter circuitry or radio frequencyreceiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The second integratedcircuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal assembly supported by the package substrate anddisposed between the first integrated circuit and the package substrate,and a second integrated circuit supported by the package substrate. Thesecond integrated circuit includes a low noise amplifier that includes afirst inductor, an amplification circuit, and a second inductormagnetically coupled to the first inductor to provide negative feedbackto linearize the low noise amplifier.

The amplification circuit can receive a radio frequency signal by way ofthe first inductor. The low noise amplifier can include an inputmatching circuit that includes the first inductor. The input matchingcircuit can further include a series inductor having a first endconfigured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The input matching circuitcan further include a shunt capacitor electrically coupled to the firstend of the series inductor. The input matching circuit can furtherinclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can further include a cascode transistor in series with thecommon source amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can further include a cascode transistor in serieswith the common emitter amplifier.

The crystal assembly can include a crystal, an input terminal configuredto receive a first signal, an output terminal configured to output asecond signal, a conductive pillar, and an enclosure configured toenclose the crystal. The conductive pillar can be formed at leastpartially within a side of the enclosure and extending from a topsurface to a bottom surface of the enclosure, and the conductive pillarcan be configured to conduct a third signal distinct from the first andsecond signals. The crystal assembly can include a plurality of theconductive pillars along one or more of the sides of the enclosure, inwhich each conductive pillar of the plurality of the conductive pillarsextends from the top surface of the enclosure to the bottom surface ofthe enclosure.

The crystal assembly, the first integrated circuit, and the secondintegrated circuit can be disposed on a first side of the packagesubstrate. The crystal assembly and the first integrated circuit can bedisposed on a first side of the package substrate, and the secondintegrated circuit can be disposed on a second side of the packagesubstrate opposite the first side. The first integrated circuit can bedisposed between the crystal assembly and the second integrated circuit.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The first integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The secondintegrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a front end integrated circuit supported by thepackage substrate, and a stacked filter assembly supported by thepackage substrate. The front end integrated circuit includes a low noiseamplifier that includes a first inductor, an amplification circuit, anda second inductor magnetically coupled to the first inductor to providenegative feedback to linearize the low noise amplifier. The stackedfilter assembly is configured to filter a signal associated with thefront end integrated circuit.

The amplification circuit can receive a radio frequency signal by way ofthe first inductor. The low noise amplifier can include an inputmatching circuit that includes the first inductor. The input matchingcircuit can further include a series inductor having a first endconfigured to receive the radio frequency signal and a second endelectrically coupled to the first inductor. The input matching circuitcan further include a shunt capacitor electrically coupled to the firstend of the series inductor. The input matching circuit can furtherinclude a direct current blocking capacitor configured to provide theradio frequency signal to the series inductor.

The amplification circuit can include a common source amplifier and thesecond inductor can be a source degeneration inductor. The amplificationcircuit can further include a cascode transistor in series with thecommon source amplifier.

The amplification circuit can include a common emitter amplifier and thesecond inductor can be an emitter degeneration inductor. Theamplification circuit can further include a cascode transistor in serieswith the common emitter amplifier.

The stacked filter assembly can include a plurality of passivecomponents each packaged as a surface mount device. At least one passivecomponent can be in direct communication with the package substrate andat least another passive component can be supported above the packagesubstrate by the at least one passive component that is in the directcommunication with the package substrate. The stacked filter assemblycan include at least one of a pi-filter circuit, a bandpass filtercircuit, a band reject filter circuit, or a notch filter circuit.

The packaged module can include an other integrated circuit supported bythe package substrate. The stacked filter assembly, the front endintegrated circuit, and the other integrated circuit can be disposed ona first side of the package substrate. The stacked filter assembly andthe other circuit can be disposed on a first side of the packagesubstrate, and the front end integrated circuit can be disposed on asecond side of the package substrate opposite the first side. The otherintegrated circuit can be disposed between the stacked filter assemblyand the second integrated circuit. The other integrated circuit caninclude a microprocessor and at least one of radio frequency transmittercircuitry or radio frequency receiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The other integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The frontend integrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a front end system that includes alow noise amplifier in a receive path of the front end system, a switchcoupled to the low noise amplifier, an overload protection circuitconfigured to adjust an impedance of the switch based on a signal levelof the low noise amplifier to provide overload protection for the lownoise amplifier, and a multi-mode power amplifier circuit in a transmitpath of the front end system. The multi-mode power amplifier circuitincludes a stacked output stage including a transistor stack of two ormore transistors. The multi-mode power amplifier circuit includes a biascircuit configured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifiercircuit.

The switch can be an antenna-side switch. The antenna-side switch canhave a first throw electrically coupled to an input of the low noiseamplifier and a second throw electrically coupled to an output of themulti-mode power amplifier circuit.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

A wireless communication device can include the front end system. Thefront end system can be embodied on a single integrated circuit. Thesingle integrated circuit can be a semiconductor-on-insulator die. Thefront end system can be embodied in a packaged module.

Another aspect of this disclosure is a front end system that includes alow noise amplifier in a receive path of the front end system, a switchcoupled to the low noise amplifier, an overload protection circuitconfigured to adjust an impedance of the switch based on a signal levelof the low noise amplifier to provide overload protection for the lownoise amplifier, and a power amplifier in a transmit path of the frontend system. The power amplifier includes an injection-locked oscillatordriver stage.

The switch can be an antenna-side switch. The antenna-side switch canhave a first throw electrically coupled to an input of the low noiseamplifier and a second throw electrically coupled to an output of themulti-mode power amplifier circuit.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

A wireless communication device can include the front end system. Thefront end system can be embodied on a single integrated circuit. Thesingle integrated circuit can be a semiconductor-on-insulator die. Thefront end system can be embodied in a packaged module.

Another aspect of this disclosure is a front end integrated circuit thatincludes a low noise amplifier system, an input pad configured toreceive a control signal, and an overstress protection circuit. The lownoise amplifier system includes a switch, a low noise amplifierincluding an input electrically coupled to the switch, and an overloadprotection circuit configured to adjust an impedance of the switch basedon a signal level of the low noise amplifier. The low noise amplifier iscontrollable by the control signal. The overstress protection circuitincludes an overstress sensing circuit electrically connected betweenthe input pad and a first supply node, an impedance element electricallyconnected between the input pad and a signal node, and a controllableclamp electrically connected between the signal node and the firstsupply node. The overstress sensing circuit is configured to activatethe controllable clamp in response to detecting an electrical overstressevent at the input pad.

The switch can be an antenna-side switch.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

A wireless communication device can include the front end integratedcircuit. A system board can include the front end integrated circuit.The front end integrated circuit can be embodied on asemiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a radio frequency shielding structure extending abovethe package substrate, a front end integrated circuit positioned in aninterior of the radio frequency shielding structure, and an antenna onthe package substrate external to the radio frequency shieldingstructure. The front end integrated circuit includes a switch, a lownoise amplifier including an input electrically coupled to the switch,and an overload protection circuit configured to adjust an impedance ofthe switch based on a signal level of the low noise amplifier.

The radio frequency shielding structure can include a plurality of wirebonds disposed between the antenna and the front end integrated circuit.The radio frequency shielding structure can include wire bond wallsdisposed around at least two sides of the front end integrated circuit.The radio frequency shielding structure can include a shielding layersubstantially parallel to the package substrate, and the front endintegrated circuit can be disposed between the shielding layer and thepackage substrate. The shielding layer can include copper. The packagedmodule can further include a protective layer over the shielding layersuch that the shielding layer is disposed between the protective layerand the front end integrated circuit. The protective layer can includetitanium.

The antenna can be a multi-layer antenna. A first portion of the antennacan be on a first side of the package substrate and a second portion ofthe antenna can be on a second side of the package substrate, in whichthe second side opposes the first side.

The switch can be an antenna-side switch electrically coupled to theantenna. The antenna-side switch can be configured to selectivelyelectrically couple the low noise amplifier to the antenna.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes amulti-layer substrate including a ground plane, an antenna on a firstside of the multi-layer substrate, and a front end integrated circuit ona second side of the multi-layer substrate. The front end integratedcircuit includes a switch and an overload protection circuit configuredto adjust an impedance of the switch based on a signal level of the lownoise amplifier. The ground plane is positioned between the antenna andthe front end integrated circuit.

The switch can be an antenna-side switch and the low noise amplifier caninclude an input electrically coupled to the antenna via theantenna-side switch.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

The packaged module can include conductive features disposed around thefront end integrated circuit and electrically connected to the groundplane, the conductive features and the ground plane can be operable toprovide shielding to the front end integrated circuit. The conductivefeatures can include solder bumps. The packaged module can include amolding material around the front end integrated circuit, and a viaextending through the molding material to electrically connect theground plane and a solder bump of the solder bumps. The antenna can be afolded quarter wave antenna. The antenna can be a loop antenna.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal supported by the package substrate, and a secondintegrated circuit supported by the package substrate. The firstintegrated circuit is disposed between the crystal and the packagesubstrate. The second integrated circuit includes a switch, a low noiseamplifier electrically coupled to the switch, and an overload protectioncircuit configured to adjust an impedance of the switch based on asignal level of the low noise amplifier to provide overload protection.

The switch can be an antenna-side switch and the low noise amplifier caninclude an input electrically coupled to the switch.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

The crystal, the first integrated circuit, and the second integratedcircuit can be disposed on a first side of the package substrate. Thecrystal and the first integrated circuit can be disposed on a first sideof the package substrate, and the second integrated circuit can bedisposed on a second side of the package substrate opposite the firstside. The first integrated circuit can include a microprocessor and atleast one of radio frequency transmitter circuitry or radio frequencyreceiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The second integratedcircuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal assembly supported by the package substrate anddisposed between the first integrated circuit and the package substrate,and a second integrated circuit supported by the package substrate. Thesecond integrated circuit includes a switch, a low noise amplifierelectrically coupled to the switch, and an overload protection circuitconfigured to adjust an impedance of the switch based on a signal levelof the low noise amplifier to provide overload protection.

The switch can be an antenna-side switch and the low noise amplifier caninclude an input electrically coupled to the switch.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

The crystal assembly can include a crystal, an input terminal configuredto receive a first signal, an output terminal configured to output asecond signal, a conductive pillar, and an enclosure configured toenclose the crystal. The conductive pillar can be formed at leastpartially within a side of the enclosure and extending from a topsurface to a bottom surface of the enclosure, and the conductive pillarcan be configured to conduct a third signal distinct from the first andsecond signals. The crystal assembly can include a plurality of theconductive pillars along one or more of the sides of the enclosure, inwhich each conductive pillar of the plurality of the conductive pillarsextends from the top surface of the enclosure to the bottom surface ofthe enclosure.

The crystal assembly, the first integrated circuit, and the secondintegrated circuit can be disposed on a first side of the packagesubstrate. The crystal assembly and the first integrated circuit can bedisposed on a first side of the package substrate, and the secondintegrated circuit can be disposed on a second side of the packagesubstrate opposite the first side. The first integrated circuit can bedisposed between the crystal assembly and the second integrated circuit.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The first integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The secondintegrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a front end integrated circuit supported by thepackage substrate, and a stacked filter assembly supported by thepackage substrate. The front end integrated circuit includes a switch, alow noise amplifier electrically coupled to the switch, and an overloadprotection circuit configured to adjust an impedance of the switch basedon a signal level of the low noise amplifier to provide overloadprotection. The stacked filter assembly is configured to filter a signalassociated with the front end integrated circuit.

The switch can be an antenna-side switch and the low noise amplifier caninclude an input electrically coupled to the switch.

The overload protection circuit can be configured to increase theimpedance of the switch responsive to detecting that the signal levelindicates an overload condition. The overload protection circuit can beconfigured to provide a feedback signal to an analog control input ofthe switch to adjust the impedance of the switch. The front end systemcan include a limiter enable circuit coupled between an output of theoverload protection circuit and the analog control input of the switch.The overload protection circuit can be configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can be configured to receive aswitch enable signal, and to disconnect the output of the overloadprotection circuit from the analog control input and turn off the switchresponsive to the switch enable signal being disabled.

The switch can include a field effect transistor having a gateconfigured as an analog control input. The signal level can be an outputsignal level of the low noise amplifier. The signal level can be aninput signal level of the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier, in which the detector configured to generate a detectionsignal based on detecting the signal level, and in which the erroramplifier is configured to generate a feedback signal for the switchbased on the detection signal. The detection signal can include adetection current. The error amplifier can be configured to generate thefeedback signal based on amplifying a difference between the detectioncurrent and a reference current.

The stacked filter assembly can include a plurality of passivecomponents each packaged as a surface mount device. At least one passivecomponent can be in direct communication with the package substrate andat least another passive component can be supported above the packagesubstrate by the at least one passive component that is in the directcommunication with the package substrate. The stacked filter assemblycan include at least one of a pi-filter circuit, a bandpass filtercircuit, a band reject filter circuit, or a notch filter circuit.

The packaged module can include an other integrated circuit supported bythe package substrate. The stacked filter assembly, the front endintegrated circuit, and the other integrated circuit can be disposed ona first side of the package substrate. The stacked filter assembly andthe other circuit can be disposed on a first side of the packagesubstrate, and the front end integrated circuit can be disposed on asecond side of the package substrate opposite the first side. The otherintegrated circuit can be disposed between the stacked filter assemblyand the second integrated circuit. The other integrated circuit caninclude a microprocessor and at least one of radio frequency transmittercircuitry or radio frequency receiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The other integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The frontend integrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a front end integrated circuit thatincludes a multi-mode power amplifier circuit, an input pad configuredto receive a control signal, and an overstress protection circuit. Themulti-mode power amplifier circuit includes a stacked output stageincluding a transistor stack of two or more transistors. The multi-modepower amplifier circuit includes also includes a bias circuit configuredto control a bias of at least one transistor of the transistor stackbased on a mode of the multi-mode power amplifier circuit. Themulti-mode power amplifier circuit is controllable by the controlsignal. The overstress protection circuit includes an overstress sensingcircuit electrically connected between the input pad and a first supplynode, an impedance element electrically connected between the input padand a signal node, and a controllable clamp electrically connectedbetween the signal node and the first supply node. The overstresssensing circuit is configured to activate the controllable clamp inresponse to detecting an electrical overstress event at the input pad.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

A wireless communication device can include the front end integratedcircuit. A packaged module can include the front end integrated circuit.The front end integrated circuit can be embodied on asemiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a radio frequency shielding structure extending abovethe package substrate, a front end integrated circuit positioned in aninterior of the radio frequency shielding structure, and an antenna onthe package substrate external to the radio frequency shieldingstructure. The front end integrated circuit includes a multi-mode poweramplifier circuit that includes a stacked output stage including atransistor stack of two or more transistors, and a bias circuit thatcontrols a bias of at least one transistor of the transistor stack basedon a mode of the multi-mode power amplifier circuit.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The radio frequency shielding structure can include a plurality of wirebonds disposed between the antenna and the front end integrated circuit.The radio frequency shielding structure can include wire bond wallsdisposed around at least two sides of the front end integrated circuit.The radio frequency shielding structure can include a shielding layersubstantially parallel to the package substrate, and the front endintegrated circuit can be disposed between the shielding layer and thepackage substrate. The shielding layer can include copper. The packagedmodule can further include a protective layer over the shielding layersuch that the shielding layer is disposed between the protective layerand the front end integrated circuit. The protective layer can includetitanium.

The antenna can be a multi-layer antenna. A first portion of the antennacan be on a first side of the package substrate and a second portion ofthe antenna can be on a second side of the package substrate, in whichthe second side opposes the first side.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes amulti-layer substrate including a ground plane, an antenna on a firstside of the multi-layer substrate, and a front end integrated circuit ona second side of the multi-layer substrate. The front end integratedcircuit includes a multi-mode power amplifier circuit including astacked output stage including a transistor stack of two or moretransistors, and a bias circuit configured to a bias of at least onetransistor of the transistor stack based on a mode of the multi-modepower amplifier circuit. The ground plane is positioned between theantenna and the front end integrated circuit.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The packaged module can include conductive features disposed around thefront end integrated circuit and electrically connected to the groundplane, the conductive features and the ground plane can be operable toprovide shielding to the front end integrated circuit. The conductivefeatures can include solder bumps. The packaged module can include amolding material around the front end integrated circuit, and a viaextending through the molding material to electrically connect theground plane and a solder bump of the solder bumps. The antenna can be afolded quarter wave antenna. The antenna can be a loop antenna.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal supported by the package substrate, and a secondintegrated circuit supported by the package substrate. The firstintegrated circuit is disposed between the crystal and the packagesubstrate. The second integrated circuit includes a multi-mode poweramplifier circuit including a stacked output stage including atransistor stack of two or more transistors, and a bias circuitconfigured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifiercircuit.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The crystal, the first integrated circuit, and the second integratedcircuit can be disposed on a first side of the package substrate. Thecrystal and the first integrated circuit can be disposed on a first sideof the package substrate, and the second integrated circuit can bedisposed on a second side of the package substrate opposite the firstside. The first integrated circuit can include a microprocessor and atleast one of radio frequency transmitter circuitry or radio frequencyreceiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The second integratedcircuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal assembly supported by the package substrate anddisposed between the first integrated circuit and the package substrate,and a second integrated circuit supported by the package substrate. Thesecond integrated circuit includes a multi-mode power amplifier circuitincluding a stacked output stage including a transistor stack of two ormore transistors, and a bias circuit configured to control a bias of atleast one transistor of the transistor stack based on a mode of themulti-mode power amplifier circuit.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The crystal assembly can include a crystal, an input terminal configuredto receive a first signal, an output terminal configured to output asecond signal, a conductive pillar, and an enclosure configured toenclose the crystal. The conductive pillar can be formed at leastpartially within a side of the enclosure and extending from a topsurface to a bottom surface of the enclosure, and the conductive pillarcan be configured to conduct a third signal distinct from the first andsecond signals. The crystal assembly can include a plurality of theconductive pillars along one or more of the sides of the enclosure, inwhich each conductive pillar of the plurality of the conductive pillarsextends from the top surface of the enclosure to the bottom surface ofthe enclosure.

The crystal assembly, the first integrated circuit, and the secondintegrated circuit can be disposed on a first side of the packagesubstrate. The crystal assembly and the first integrated circuit can bedisposed on a first side of the package substrate, and the secondintegrated circuit can be disposed on a second side of the packagesubstrate opposite the first side. The first integrated circuit can bedisposed between the crystal assembly and the second integrated circuit.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The first integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The secondintegrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a front end integrated circuit supported by thepackage substrate, and a stacked filter assembly supported by thepackage substrate. The front end integrated circuit includes amulti-mode power amplifier circuit including a stacked output stageincluding a transistor stack of two or more transistors, and a biascircuit configured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifiercircuit. The stacked filter assembly is configured to filter a signalassociated with the front end integrated circuit.

The bias circuit can be configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode and asa switch in a second mode. The bias circuit can be configured to biasthe transistor in a saturation region of operation in the second mode.The second mode can be associated with a lower power than the firstmode. The stacked output stage can be configured to receive a supplyvoltage having a lower voltage level in the second mode relative to thefirst mode. The stacked output stage can be operable in at least threedifferent modes. The transistor stack can include at least threetransistors in series.

The stacked filter assembly can include a plurality of passivecomponents each packaged as a surface mount device. At least one passivecomponent can be in direct communication with the package substrate andat least another passive component can be supported above the packagesubstrate by the at least one passive component that is in the directcommunication with the package substrate. The stacked filter assemblycan include at least one of a pi-filter circuit, a bandpass filtercircuit, a band reject filter circuit, or a notch filter circuit.

The packaged module can include an other integrated circuit supported bythe package substrate. The stacked filter assembly, the front endintegrated circuit, and the other integrated circuit can be disposed ona first side of the package substrate. The stacked filter assembly andthe other circuit can be disposed on a first side of the packagesubstrate, and the front end integrated circuit can be disposed on asecond side of the package substrate opposite the first side. The otherintegrated circuit can be disposed between the stacked filter assemblyand the second integrated circuit. The other integrated circuit caninclude a microprocessor and at least one of radio frequency transmittercircuitry or radio frequency receiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The other integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The frontend integrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a front end integrated circuit thatincludes a power amplifier including an injection-locked oscillatordriver stage, an input pad configured to receive a control signal, andan overstress protection circuit. The power amplifier is controllable bythe control signal. The overstress protection circuit includes anoverstress sensing circuit electrically connected between the input padand a first supply node, an impedance element electrically connectedbetween the input pad and a signal node, and a controllable clampelectrically connected between the signal node and the first supplynode. The overstress sensing circuit is configured to activate thecontrollable clamp in response to detecting an electrical overstressevent at the input pad.

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

A wireless communication device can include the front end integratedcircuit. A system board can include the front end integrated circuit.The front end integrated circuit can be embodied on asemiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a radio frequency shielding structure extending abovethe package substrate, a front end integrated circuit positioned in aninterior of the radio frequency shielding structure, and an antenna onthe package substrate external to the radio frequency shieldingstructure. The front end integrated circuit includes an injection-lockedoscillator driver stage;

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

The radio frequency shielding structure can include a plurality of wirebonds disposed between the antenna and the front end integrated circuit.The radio frequency shielding structure can include wire bond wallsdisposed around at least two sides of the front end integrated circuit.The radio frequency shielding structure can include a shielding layersubstantially parallel to the package substrate, and the front endintegrated circuit can be disposed between the shielding layer and thepackage substrate. The shielding layer can include copper. The packagedmodule can further include a protective layer over the shielding layersuch that the shielding layer is disposed between the protective layerand the front end integrated circuit. The protective layer can includetitanium.

The antenna can be a multi-layer antenna. A first portion of the antennacan be on a first side of the package substrate and a second portion ofthe antenna can be on a second side of the package substrate, in whichthe second side opposes the first side.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes amulti-layer substrate including a ground plane, an antenna on a firstside of the multi-layer substrate, and a front end integrated circuit ona second side of the multi-layer substrate. The front end integratedcircuit includes an injection-locked oscillator driver stage, the groundplane positioned between the antenna and the front end integratedcircuit.

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

The packaged module can include conductive features disposed around thefront end integrated circuit and electrically connected to the groundplane, the conductive features and the ground plane can be operable toprovide shielding to the front end integrated circuit. The conductivefeatures can include solder bumps. The packaged module can include amolding material around the front end integrated circuit, and a viaextending through the molding material to electrically connect theground plane and a solder bump of the solder bumps. The antenna can be afolded quarter wave antenna. The antenna can be a loop antenna.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal supported by the package substrate, and a secondintegrated circuit supported by the package substrate. The firstintegrated circuit is disposed between the crystal and the packagesubstrate. The second integrated circuit includes a power amplifierincluding an injection-locked oscillator driver stage.

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

The crystal, the first integrated circuit, and the second integratedcircuit can be disposed on a first side of the package substrate. Thecrystal and the first integrated circuit can be disposed on a first sideof the package substrate, and the second integrated circuit can bedisposed on a second side of the package substrate opposite the firstside. The first integrated circuit can include a microprocessor and atleast one of radio frequency transmitter circuitry or radio frequencyreceiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The second integratedcircuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal assembly supported by the package substrate anddisposed between the first integrated circuit and the package substrate,and a second integrated circuit supported by the package substrate. Thesecond integrated circuit includes a power amplifier including aninjection-locked oscillator driver stage.

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

The crystal assembly can include a crystal, an input terminal configuredto receive a first signal, an output terminal configured to output asecond signal, a conductive pillar, and an enclosure configured toenclose the crystal. The conductive pillar can be formed at leastpartially within a side of the enclosure and extending from a topsurface to a bottom surface of the enclosure, and the conductive pillarcan be configured to conduct a third signal distinct from the first andsecond signals. The crystal assembly can include a plurality of theconductive pillars along one or more of the sides of the enclosure, inwhich each conductive pillar of the plurality of the conductive pillarsextends from the top surface of the enclosure to the bottom surface ofthe enclosure.

The crystal assembly, the first integrated circuit, and the secondintegrated circuit can be disposed on a first side of the packagesubstrate. The crystal assembly and the first integrated circuit can bedisposed on a first side of the package substrate, and the secondintegrated circuit can be disposed on a second side of the packagesubstrate opposite the first side. The first integrated circuit can bedisposed between the crystal assembly and the second integrated circuit.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The first integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The secondintegrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a front end integrated circuit supported by thepackage substrate, and a stacked filter assembly supported by thepackage substrate. The front end integrated circuit includes a poweramplifier including an injection-locked oscillator driver stage. Thestacked filter assembly is configured to filter a signal associated withthe front end integrated circuit.

The injection-locked oscillator driver stage can include an output balunconfigured to provide a differential to singled-ended signal conversion.The injection-locked oscillator driver stage can be powered by asubstantially fixed supply voltage. The injection-locked oscillatordriver stage can be configured to receive a single-ended input signal,and the injection-locked oscillator driver stage can include an inputtransformer configured to convert the single-ended input signal to adifferential input signal.

The injection-locked oscillator driver stage can include a negativetransconductance circuit electrically connected to an inductor-capacitortank, in which the negative transconductance circuit configured toprovide energy to the inductor-capacitor tank to maintain oscillation.The negative transconductance circuit can include a pair ofcross-coupled metal-oxide-semiconductor transistors. Theinjection-locked oscillator driver stage can further include a signalinjecting circuit configured to provide signal injection to theinductor-capacitor tank based on a radio frequency input signal.

The stacked filter assembly can include a plurality of passivecomponents each packaged as a surface mount device. At least one passivecomponent can be in direct communication with the package substrate andat least another passive component can be supported above the packagesubstrate by the at least one passive component that is in the directcommunication with the package substrate. The stacked filter assemblycan include at least one of a pi-filter circuit, a bandpass filtercircuit, a band reject filter circuit, or a notch filter circuit.

The packaged module can include an other integrated circuit supported bythe package substrate. The stacked filter assembly, the front endintegrated circuit, and the other integrated circuit can be disposed ona first side of the package substrate. The stacked filter assembly andthe other circuit can be disposed on a first side of the packagesubstrate, and the front end integrated circuit can be disposed on asecond side of the package substrate opposite the first side. The otherintegrated circuit can be disposed between the stacked filter assemblyand the second integrated circuit. The other integrated circuit caninclude a microprocessor and at least one of radio frequency transmittercircuitry or radio frequency receiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The other integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The frontend integrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a radio frequency shielding structure extending abovethe package substrate, a front end integrated circuit positioned in aninterior of the radio frequency shielding structure, and an antenna onthe package substrate external to the radio frequency shieldingstructure. The front end integrated circuit includes a pad, anoverstress protection circuit, and an internal circuit electricallyconnected to a signal node. The overstress protection circuit includesan overstress sensing circuit electrically connected between the pad anda first supply node, an impedance element electrically connected betweenthe pad and the signal node, and a controllable clamp electricallyconnected between the signal node and the first supply node. Theoverstress sensing circuit is configured to activate the controllableclamp in response to detecting an electrical overstress event at thepad.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

The radio frequency shielding structure can include a plurality of wirebonds disposed between the antenna and the front end integrated circuit.The radio frequency shielding structure can include wire bond wallsdisposed around at least two sides of the front end integrated circuit.The radio frequency shielding structure can include a shielding layersubstantially parallel to the package substrate, and the front endintegrated circuit can be disposed between the shielding layer and thepackage substrate. The shielding layer can include copper. The packagedmodule can further include a protective layer over the shielding layersuch that the shielding layer is disposed between the protective layerand the front end integrated circuit. The protective layer can includetitanium.

The antenna can be a multi-layer antenna. A first portion of the antennacan be on a first side of the package substrate and a second portion ofthe antenna can be on a second side of the package substrate, in whichthe second side opposes the first side.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes amulti-layer substrate including a ground plane, an antenna on a firstside of the multi-layer substrate, and a front end integrated circuit ona second side of the multi-layer substrate. The front end integratedcircuit includes a pad, an overstress protection circuit, and aninternal circuit electrically connected to a signal node. The overstressprotection circuit includes an overstress sensing circuit electricallyconnected between the pad and a first supply node, an impedance elementelectrically connected between the pad and the signal node, and acontrollable clamp electrically connected between the signal node andthe first supply node. The overstress sensing circuit is configured toactivate the controllable clamp in response to detecting an electricaloverstress event at the pad. The ground plane is positioned between theantenna and the front end integrated circuit.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

The packaged module can include conductive features disposed around thefront end integrated circuit and electrically connected to the groundplane, the conductive features and the ground plane can be operable toprovide shielding to the front end integrated circuit. The conductivefeatures can include solder bumps. The packaged module can include amolding material around the front end integrated circuit, and a viaextending through the molding material to electrically connect theground plane and a solder bump of the solder bumps. The antenna can be afolded quarter wave antenna. The antenna can be a loop antenna.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The front end integratedcircuit can be embodied on a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal supported by the package substrate, and a secondintegrated circuit supported by the package substrate. The firstintegrated circuit is disposed between the crystal and the packagesubstrate. The second integrated circuit includes a pad, an overstressprotection circuit, and an internal circuit electrically connected to asignal node. The overstress protection circuit includes an overstresssensing circuit electrically connected between the pad and a firstsupply node, an impedance element electrically connected between the padand the signal node, and a controllable clamp electrically connectedbetween the signal node and the first supply node. The overstresssensing circuit is configured to activate the controllable clamp inresponse to detecting an electrical overstress event at the pad.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

The crystal, the first integrated circuit, and the second integratedcircuit can be disposed on a first side of the package substrate. Thecrystal and the first integrated circuit can be disposed on a first sideof the package substrate, and the second integrated circuit can bedisposed on a second side of the package substrate opposite the firstside. The first integrated circuit can include a microprocessor and atleast one of radio frequency transmitter circuitry or radio frequencyreceiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The second integratedcircuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a first integrated circuit supported by the packagesubstrate, a crystal assembly supported by the package substrate anddisposed between the first integrated circuit and the package substrate,and a second integrated circuit supported by the package substrate. Thesecond integrated circuit includes a pad, an overstress protectioncircuit, and an internal circuit electrically connected to a signalnode. The overstress protection circuit includes an overstress sensingcircuit electrically connected between the pad and a first supply node,an impedance element electrically connected between the pad and thesignal node, and a controllable clamp electrically connected between thesignal node and the first supply node. The overstress sensing circuit isconfigured to activate the controllable clamp in response to detectingan electrical overstress event at the pad.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

The crystal assembly can include a crystal, an input terminal configuredto receive a first signal, an output terminal configured to output asecond signal, a conductive pillar, and an enclosure configured toenclose the crystal. The conductive pillar can be formed at leastpartially within a side of the enclosure and extending from a topsurface to a bottom surface of the enclosure, and the conductive pillarcan be configured to conduct a third signal distinct from the first andsecond signals. The crystal assembly can include a plurality of theconductive pillars along one or more of the sides of the enclosure, inwhich each conductive pillar of the plurality of the conductive pillarsextends from the top surface of the enclosure to the bottom surface ofthe enclosure.

The crystal assembly, the first integrated circuit, and the secondintegrated circuit can be disposed on a first side of the packagesubstrate. The crystal assembly and the first integrated circuit can bedisposed on a first side of the package substrate, and the secondintegrated circuit can be disposed on a second side of the packagesubstrate opposite the first side. The first integrated circuit can bedisposed between the crystal assembly and the second integrated circuit.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The first integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The secondintegrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a packaged module that includes apackage substrate, a front end integrated circuit supported by thepackage substrate, and a stacked filter assembly supported by thepackage substrate. The front end integrated circuit includes a pad, anoverstress protection circuit, and an internal circuit electricallyconnected to a signal node. The overstress protection circuit includesan overstress sensing circuit electrically connected between the pad anda first supply node, an impedance element electrically connected betweenthe pad and the signal node, and a controllable clamp electricallyconnected between the signal node and the first supply node. Theoverstress sensing circuit is configured to activate the controllableclamp in response to detecting an electrical overstress event at thepad. The stacked filter assembly is configured to filter a signalassociated with the front end integrated circuit.

The overstress sensing circuit can include a plurality of diodes and afirst field-effect transistor configured to activate in response to theelectrical overstress event generating a flow of current through theplurality of diodes. The controllable clamp can include a secondfield-effect transistor electrically connected with the firstfield-effect transistor as a current mirror. The impedance element caninclude a resistor. The overstress protection circuit can furtherinclude an overshoot limiting circuit electrically connected between thesignal node and a second supply node. The overstress protection circuitcan include at least one diode configured to control a trigger voltageof the overshoot limiting circuit. The first supply node can be a groundrail and the second supply node can be a power supply rail.

The stacked filter assembly can include a plurality of passivecomponents each packaged as a surface mount device. At least one passivecomponent can be in direct communication with the package substrate andat least another passive component can be supported above the packagesubstrate by the at least one passive component that is in the directcommunication with the package substrate. The stacked filter assemblycan include at least one of a pi-filter circuit, a bandpass filtercircuit, a band reject filter circuit, or a notch filter circuit.

The packaged module can include an other integrated circuit supported bythe package substrate. The stacked filter assembly, the front endintegrated circuit, and the other integrated circuit can be disposed ona first side of the package substrate. The stacked filter assembly andthe other circuit can be disposed on a first side of the packagesubstrate, and the front end integrated circuit can be disposed on asecond side of the package substrate opposite the first side. The otherintegrated circuit can be disposed between the stacked filter assemblyand the second integrated circuit. The other integrated circuit caninclude a microprocessor and at least one of radio frequency transmittercircuitry or radio frequency receiver circuitry.

A wireless communication device can include the packaged module. Asystem board can include the packaged module. The other integratedcircuit can include a microprocessor and at least one of radio frequencytransmitter circuitry or radio frequency receiver circuitry. The frontend integrated circuit can be a semiconductor-on-insulator die.

Another aspect of this disclosure is a low noise amplifier system thatincludes a low noise amplifier, a switch, and an overload protectioncircuit. The low noise amplifier includes a first inductor, anamplification circuit configured to amplify a radio frequency signal,and a second inductor magnetically coupled to the first inductor toprovide negative feedback to linearize the low noise amplifier. Theswitch is coupled to the amplification circuit. The overload protectioncircuit is configured to adjust an impedance of the switch based on asignal level associated with the radio frequency signal to provideoverload protection for the low noise amplifier.

The switch can be an input switch configured to provide the radiofrequency signal to the amplification circuit for amplification. Theoverload protection circuit can provide a feedback signal to an analogcontrol input of the input switch to adjust the impedance of the inputswitch. The overload protection circuit can increase the impedance ofthe input switch responsive to detecting that the signal level indicatesan overload condition. The low noise amplifier system can also includelimiter enable circuit coupled between an output of the overloadprotection circuit and the analog control input of the input switch, inwhich the overload protection circuit is configured to provide thefeedback signal to the analog control input by way of the limiter enablecircuit. The limiter enable circuit can receive a switch enable signaland disconnect the output of the overload protection circuit from theanalog control input and turn off the input switch responsive to theswitch enable signal being disabled. The input switch can include afield effect transistor having a gate configured as the analog controlinput.

The signal level can be an output signal level of the low noiseamplifier. Alternatively, the signal level can be an input signal levelof the low noise amplifier.

The overload protection circuit can include a detector and an erroramplifier. The detector can generate a detection signal based ondetecting the signal level. The error amplifier can generate a feedbacksignal for the switch based on the detection signal. The detector caninclude a bipolar transistor configured to saturate in response to anoverload condition of the low noise amplifier. The detector can includea capacitor configured to filter a current flowing through the bipolartransistor, and the detector can generate the detection signal based ona voltage across the capacitor. The detection signal can include adetection current. The error amplifier can generate the feedback signalbased on amplifying a difference between the detection current and areference current.

The switch can provide the radio frequency signal to the amplificationcircuit by way of a matching circuit that includes the first inductor.The matching circuit can include a direct current blocking capacitor anda series inductor in series between the direct current blockingcapacitor and the first inductor. The direct current blocking capacitor,the series inductor, and the first inductor can be arranged in seriesbetween the switch and a control terminal of the amplification circuit.

The first inductor and the second inductor can together function as atransformer having a primary winding in series with an input of theamplification circuit and a secondary winding connected between atransistor of the amplification circuit and a low voltage reference. Thesecond inductor can be configured as a degeneration inductor. The switchcan be in series with the second inductor. For instance, the secondinductor can be in arranged in series between the switch and theamplification circuit.

The amplification circuit can include a field effect transistor having asource, and the second inductor can be configured as a sourcedegeneration inductor. The first inductor and the second inductor cantogether function as a transformer having a primary winding in serieswith a gate of the field effect transistor and a secondary windingconnected at the source of the field effect transistor.

The amplification circuit can include a bipolar transistor having anemitter, and the second inductor can be configured as an emitterdegeneration inductor. The first inductor and the second inductor cantogether function as a transformer having a primary winding in serieswith a base of the bipolar transistor and a secondary winding connectedat the emitter of the bipolar transistor.

The low noise amplifier system can include a series inductor arranged inseries between the switch and the first inductor. The low noiseamplifier system can include a direct current blocking capacitorelectrically connected between the switch and the series inductor. Thelow noise amplifier system can include a shunt capacitor electricallyconnected to a node between the switch and the series inductor.

Another aspect of this disclosure is a front end system comprising thatincludes a low noise amplifier, an input switch, and an overloadprotection circuit. The low noise amplifier includes a first inductor,an amplification circuit configured to receive a radio frequency signalby way of the first inductor and to amplify the radio frequency signal,and a second inductor magnetically coupled to the first inductor toprovide negative feedback to linearize the low noise amplifier. Theinput switch has a control input arranged to control an impedance of theinput switch. The input switch includes a first throw coupled to thefirst inductor. The overload protection circuit is configured to providea feedback signal to the control input of the input switch based onbased on a signal level associated with the low noise amplifier.

The front end system can include a bypass path. The input switch caninclude a second throw electrically connected to the bypass path. Thefront end system can further include a power amplifier. The input switchcan further include a third throw electrically connected to the poweramplifier. The low noise amplifier, the bypass path, the multi-throwswitch, and the power amplifier can be embodied on a single die.

The front end system can include an output switch having at least afirst throw electrically connected to an output of the low noiseamplifier.

The input switch can electrically connect an input of the low noiseamplifier to an antenna in a first state.

The low noise amplifier, the input switch, and the overload protectioncircuit can be embodied on a single die.

The front end system can include a package enclosing the low noiseamplifier, the input switch, and the overload protection circuit.

In the front end system, the control input can be an analog input.

The front end system can include one or more suitable features of any ofthe low noise amplifier systems discussed herein.

Another aspect of this disclosure is a wireless communication devicethat includes a front end system and an antenna in communication withthe front end system. The front end system comprising that includes alow noise amplifier, an input switch, and an overload protectioncircuit. The low noise amplifier includes a first inductor, anamplification circuit configured to receive a radio frequency signal byway of the first inductor and to amplify the radio frequency signal, anda second inductor magnetically coupled to the first inductor to providenegative feedback to linearize the low noise amplifier. The input switchhas a control input arranged to control an impedance of the inputswitch. The input switch includes a first throw coupled to the firstinductor. The overload protection circuit is configured to provide afeedback signal to the control input of the input switch based on basedon a signal level associated with the low noise amplifier.

The front end system can be configured to process Bluetooth signals. Thefront end system can be configured to process ZigBee signals. The frontend system can be configured to process Wi-Fi signals.

The front end system can include one or more suitable features of any ofthe front end systems discussed herein.

The wireless communication device can be a mobile phone. The wirelesscommunication device can be configured for wireless communication over apersonal area network.

Another aspect of this disclosure is a method of providing overloadprotection in a low noise amplifier system. The method includesamplifying a radio frequency signal using the low noise amplifier, thelow noise amplifier including first and second inductors magneticallycoupled to each other to provide negative feedback to linearize the lownoise amplifier; detecting that a signal level associated with the lownoise amplifier is indicative of an overload condition; and increasingan impedance of a switch coupled to an amplification circuit of the lownoise amplifier responsive to said detecting to thereby provide overloadprotection.

Detecting the signal level can include detecting an output signal levelof the low noise amplifier. Alternatively, detecting the signal levelcan include detecting an input signal level of the low noise amplifier.

The switch can be an input switch configured to provide the radiofrequency signal to the low noise amplifier. The method can includeselectively connecting an output of an overload protection circuit to ananalog control input of the input switch. The method can also includedisconnecting the output of the overload protection circuit from theanalog control input responsive to a switch enable signal beingdisabled.

The method can include generating a feedback signal based on detectingthe signal level associated with the low noise amplifier using an erroramplifier of the overload protection circuit, in which increasing theimpedance of the switch is responsive to the feedback signal. Detectingcan include generating a detection current. Generating the feedbacksignal can include amplifying a difference between the detection currentand a reference current.

Detecting the signal level can include saturating a bipolar transistorin response to the overload condition. Detecting the signal level canalso include filtering a current flowing through the bipolar transistorusing a capacitor and controlling the detected signal level based on avoltage across the capacitor.

The switch can include a field effect transistor. Increasing theimpedance of the switch can include providing an analog signal to a gateof the field effect transistor.

The second inductor can be a source degeneration inductor.Alternatively, the second inductor can be an emitter degenerationinductor. The switch can be arranged in series with the second inductor.

The switch can be an input switch configured to provide the radiofrequency signal to the low noise amplifier. A series inductor can bearranged in series between the input switch and the first inductor. Themethod can include blocking a direct current signal component associatedwith the radio frequency signal using a blocking capacitor electricallyconnected between the input switch and the series inductor. A shuntcapacitor can be electrically connected to a node between the inputswitch and the series inductor.

Another aspect of this disclosure is a radio frequency amplifier thatincludes an input terminal configured to receive a radio frequency inputsignal, an output terminal configured to provide a radio frequencyoutput signal, a driver stage including an injection-locked oscillatorconfigured to amplify the radio frequency input signal to generate anamplified radio frequency signal, and a stacked output stage configuredto further amplify the amplified radio frequency to generate the outputradio frequency signal. The stacked output stage includes a transistorstack of at least a first transistor and a second transistor in serieswith one another.

The stacked output stage can be operable in at least a first mode and asecond mode. The radio frequency amplifier can include a bias circuitconfigured to bias the second transistor to a linear region of operationin the first mode, and to bias the second transistor as a switch in thesecond mode. The bias circuit can be configured to bias the secondtransistor in a saturation region of operation in the second mode. Thebias circuit can be configured to dynamically generate biases for thefirst transistor and for the second transistor based on a mode controlsignal. The second transistor can be a field effect transistor and thebias circuit can be configured to bias the second transistor such thatthe second transistor has a drain-to-source voltage of less than 75 mVin the second mode. The second transistor can be a field effecttransistor and the bias circuit can be configured to bias the secondtransistor such that the second transistor has a drain-to-source voltageof less than 100 mV in the second mode. The second mode can beassociated with a lower power than the first mode. The stacked outputstage can be operable in at least three different modes. The stackedoutput stage can be configured to receive a supply voltage, in which thesupply voltage has a lower voltage level in the second mode relative tothe first mode. The radio frequency amplifier can include a switchconfigured to provide the amplified radio frequency signal to the secondtransistor in the first mode, and to provide the amplified radiofrequency signal to the first transistor in the second mode.

The stacked output stage can include a third transistor in series withthe first and second transistors. The second transistor can be arrangedin series between the first transistor and the third transistor. Thefirst transistor, the second transistor, and the third transistor can besilicon-on-insulator transistors. The second transistor can be a fieldeffect transistor having a source electrically connected to the firsttransistor and a drain electrically connected to the third transistor.The first transistor can be a common source transistor, the secondtransistor can be a common gate transistor, and the third transistor canbe a common gate transistor. The first transistor can be a commonemitter transistor, the second transistor can be a common basetransistor, and the third transistor can be a common base transistor.The transistor stack can include at least four transistors in serieswith each other.

The first transistor and the second transistor can besemiconductor-on-insulator transistors. The first transistor can be acommon source transistor, and the second transistor can be a common gatetransistor. The first transistor can be a common emitter transistor, andthe second transistor can be a common base transistor.

The driver stage can be a power amplifier input stage, and the stackedoutput stage can be a power amplifier output stage.

The radio frequency amplifier can include an output matching networkelectrically connected to the output terminal. The output matchingnetwork can be a class F output matching network. The output matchingnetwork can be a class AB output matching network.

The stacked output stage can have an adjustable supply voltage thatchanges with a mode of the radio frequency amplifier.

The radio frequency amplifier can include an interstage matching networkproviding impedance matching between an output of the driver stage andan input to the stacked output stage.

The injection-locked oscillator can include an output balun configuredto provide a differential to singled-ended signal conversion. The radiofrequency input signal can be a single-ended input signal, and theinjection-locked oscillator can include an input transformer configuredto convert the single-ended input signal to a differential input signal.

The driver stage can be powered by a substantially fixed supply voltage.The stacked output stage can have an adjustable supply voltage thatchanges with a mode of the radio frequency amplifier.

The radio frequency input signal can be a modulated signal having asubstantially constant signal envelope.

The injection-locked oscillator can include a negative transconductancecircuit electrically connected to an inductor-capacitor tank, and thenegative transconductance circuit can be configured to provide energy tothe inductor-capacitor tank to maintain oscillations. The negativetransconductance circuit can include a pair of cross-coupledmetal-oxide-semiconductor transistors. The injection-locked oscillatorcan further include a bias metal-oxide-semiconductor transistor having agate bias voltage that controls a bias current of the negativetransconductance circuit. The injection-locked oscillator can include asignal injecting circuit configured to provide signal injection to theinductor-capacitor tank based on the radio frequency input signal. Theinjection-locked oscillator can include an output transformer configuredto generate an amplified radio frequency signal at the output of thedriver stage. The inductor-capacitor tank can include an inductorassociated with an inductance of the output transformer and a capacitorassociated with a parasitic capacitance of the negative transconductancecircuit.

Another aspect of this disclosure is a method of radio frequency signalamplification. The method includes receiving a radio frequency inputsignal as an input to a radio frequency amplifier, the radio frequencyamplifier including a driver stage and a stacked output stage;amplifying the radio frequency input signal to generate an amplifiedradio frequency signal using an injection-locked oscillator of thedriver stage; and further amplifying the amplified radio frequencysignal using a transistor stack of the output stage, the transistorstack including at least a first transistor and a second transistor inseries with one another.

The method can further include operating the stacked output stage in aselected mode chosen from at least a first mode and a second mode. Themethod can further include biasing the second transistor to a linearregion of operation in the first mode, and biasing the second transistoras a switch in the second mode. The method can further include biasingthe second transistor in a saturation region of operation in the secondmode. The second mode can be associated with a lower power than thefirst mode.

The method can further include providing the stacked output stage withan adjustable supply voltage having a lower voltage level in the secondmode relative to the first mode. The method can include providing outputmatching at an output of the radio frequency amplifier using an outputmatching network. The method can include providing interstage matchingbetween an output of the driver stage and an input to the stacked outputstage using an interstage matching network.

The method can include providing a differential to singled-ended signalconversion at an output of the injection-locked oscillator. The methodcan include powering the driver stage using a substantially fixed supplyvoltage. The method can include changing an adjustable supply voltage ofthe stacked output stage based on a mode of the radio frequencyamplifier. Receiving the radio frequency input signal can includereceiving a modulated signal having a substantially constant signalenvelope. The method can include providing a single-ended todifferential signal conversion at an input of the injection-lockedoscillator using an input transformer. The method can includemaintaining oscillators of an inductor-capacitor tank of theinjection-locked oscillator using a negative transconductance circuit.The method can include controlling a bias current of the negativetransconductance circuit by controlling a gate bias of a biasmetal-oxide-semiconductor transistor. The method can include injectingthe radio frequency input signal into the inductor-capacitor tank usinga signal injecting circuit.

Another aspect of this disclosure is a front end system that includes alow noise amplifier, a power amplifier including a driver stage and astacked output stage, and a switch electrically connected to the lownoise amplifier and the power amplifier. The driver stage includes aninjection-locked oscillator configured to amplify a radio frequencyinput signal to generate an amplified radio frequency signal. Thestacked output stage is configured to further amplify the amplifiedradio frequency to generate an output radio frequency signal. Thestacked output stage includes a transistor stack of at least a firsttransistor and a second transistor in series with one another.

The front end system can be implemented on a multi-chip module. Thefront end system can be implemented on an integrated circuit. The lownoise amplifier and the power amplifier can be embodied on a single die.The die can be a semiconductor-on-insulator die. The front end systemcan include a package enclosing the power amplifier, the low noiseamplifier, and the switch.

The switch can be a first multi-throw switch having at least a firstthrow electrically coupled to the power amplifier and a second throwelectrically coupled to the low noise amplifier. The first multi-throwswitch can further include a third throw. The front end system caninclude a bypass path electrically coupled to the third throw. The frontend system can further include a second multi-throw switch having atleast a first throw electrically connected to the power amplifier and asecond throw electrically connected to the low noise amplifier. Thefirst multi-throw switch can be configured to electrically connect anoutput of the power amplifier to an antenna in a first state, and thefirst multi-throw switch can be configured to electrically connect thelow noise amplifier to the antenna in a second state. The firstmulti-throw switch can have at least two poles.

The front end system can include an antenna electrically coupled to theswitch.

The front end system can include a supply control circuit configured togenerate a supply voltage for the stacked output stage. The supplycontrol circuit can include a DC-to-DC converter.

The stacked output stage can be operable in at least a first mode and asecond mode. The front end system can include a bias circuit configuredto bias the second transistor to a linear region of operation in thefirst mode, and to bias the second transistor as a switch in the secondmode. The bias circuit can be configured to bias the second transistorin a saturation region of operation in the second mode. The bias circuitcan be configured to dynamically generate biases for the firsttransistor and for the second transistor based on a mode control signal.The second transistor can be a field effect transistor and the biascircuit can be configured to bias the second transistor such that thesecond transistor has a drain-to-source voltage of less than 75 mV inthe second mode. The second transistor can be a field effect transistorand the bias circuit can be configured to bias the second transistorsuch that the second transistor has a drain-to-source voltage of lessthan 100 mV in the second mode. The second mode can be associated with alower power than the first mode. The stacked output stage can beoperable in at least three different modes. The stacked output stage canbe configured to receive a supply voltage, in which the supply voltagehas a lower voltage level in the second mode relative to the first mode.The front end system can include a switch configured to provide theamplified radio frequency signal to the second transistor in the firstmode, and to provide the amplified radio frequency signal to the firsttransistor in the second mode.

The stacked output stage can include a third transistor in series withthe first and second transistors. The second transistor can be arrangedin series between the first transistor and the third transistor. Thefirst transistor, the second transistor, and the third transistor can besilicon-on-insulator transistors. The second transistor can be a fieldeffect transistor having a source electrically connected to the firsttransistor and a drain electrically connected to the third transistor.The first transistor can be a common source transistor, the secondtransistor can be a common gate transistor, and the third transistor canbe a common gate transistor. The first transistor can be a commonemitter transistor, the second transistor can be a common basetransistor, and the third transistor can be a common base transistor.The transistor stack can include at least four transistors in serieswith each other.

The first transistor and the second transistor can besemiconductor-on-insulator transistors. The first transistor can be acommon source transistor, and the second transistor can be a common gatetransistor. The first transistor can be a common emitter transistor, andthe second transistor can be a common base transistor.

The stacked output stage can have an adjustable supply voltage thatchanges with a mode of the front end system.

The front end system can include an interstage matching networkproviding impedance matching between an output of the driver stage andan input to the stacked output stage.

The injection-locked oscillator can include an output balun configuredto provide a differential to singled-ended signal conversion. The radiofrequency input signal can be a single-ended input signal, and theinjection-locked oscillator can include an input transformer configuredto convert the single-ended input signal to a differential input signal.

The driver stage can be powered by a substantially fixed supply voltage.The stacked output stage can have an adjustable supply voltage thatchanges with a mode of the front end system.

The radio frequency input signal can be a modulated signal having asubstantially constant signal envelope.

The front end system can include an output matching network electricallyconnected to an output of the stacked output stage.

The radio frequency input signal can be a single-ended input signal, andthe injection-locked oscillator can include an input transformerconfigured to convert the single-ended input signal to a differentialinput signal.

The injection-locked oscillator can include a negative transconductancecircuit electrically connected to an inductor-capacitor tank, and thenegative transconductance circuit can be configured to provide energy tothe inductor-capacitor tank to maintain oscillations. The negativetransconductance circuit can include a pair of cross-coupledmetal-oxide-semiconductor transistors. The injection-locked oscillatorcan further include a bias metal-oxide-semiconductor transistor having agate bias voltage that controls a bias current of the negativetransconductance circuit. The injection-locked oscillator can include asignal injecting circuit configured to provide signal injection to theinductor-capacitor tank based on the radio frequency input signal. Theinjection-locked oscillator can include an output transformer configuredto generate an amplified radio frequency signal at the output of thedriver stage. The inductor-capacitor tank can include an inductorassociated with an inductance of the output transformer and a capacitorassociated with a parasitic capacitance of the negative transconductancecircuit.

Another aspect of this disclosure is a wireless communication devicethat includes a power amplifier including a driver stage and a stackedoutput stage, a transmitter configured to provide a radio frequencyinput signal to the power amplifier, a switch, and an antennaelectrically connected to an output of the stacked output stage via theswitch. The driver stage includes an injection-locked oscillatorconfigured to amplify a radio frequency input signal to generate anamplified radio frequency signal. The stacked output stage is configuredto further amplify the amplified radio frequency to generate an outputradio frequency signal. The stacked output stage includes a transistorstack of at least a first transistor and a second transistor in serieswith one another.

The wireless communication device can include a supply control circuitconfigured to generate the second supply voltage. The supply controlcircuit can be configured to receive a mode control signal from thetransmitter.

A wireless personal area network system can include the power amplifierand the transmitter, and the radio frequency input signal is a wirelesspersonal area network signal. A wireless local area network system caninclude the power amplifier and the transmitter, and the radio frequencyinput signal can be a wireless local area network signal. The poweramplifier can includes one or more features of the power amplifiersdiscussed herein.

Another aspect of this disclosure is packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate and including at least a microprocessor and oneor more of radio frequency transmitter circuitry and radio frequencyreceiver circuitry, a crystal supported by the substrate, and a seconddie supported by the substrate and implementing at least a portion of aradio frequency front end including a radio frequency power amplifier.The first die is disposed between the crystal and the substrate. Thesubstrate is disposed between the first die and the second die.

The packaged module can include an overmold enclosing the first die andthe crystal. A wireless communication device can include the packagedmodule. A system board assembly can include the packaged module.

Another aspect of this disclosure is packaged radio frequency modulethat includes a radio frequency shielding structure extending above apackage substrate, a first die supported by the package substrate and inan interior of the radio frequency shielding structure, an antennasupported by the package substrate external to the radio frequencyshielding structure, and a crystal supported by the package substrate.The first die is disposed between the crystal and the package substrate.The first die includes a radio frequency component.

The packaged radio frequency module can include an overmold enclosingthe first die, the crystal, and the antenna. A wireless communicationdevice can include the packaged radio frequency module. A system boardassembly can include the packaged radio frequency module.

Another aspect of this disclosure is a packaged radio frequency modulethat includes a radio frequency shielding structure extending above apackage substrate, a first die supported by the package substrate and inan interior of the radio frequency shielding structure, an antennasupported by the package substrate external to the radio frequencyshielding structure, and a crystal supported by the package substrate.The crystal is disposed between the first die and the package substrate.The first die includes a radio frequency component.

The packaged radio frequency module can include an overmold enclosingthe first die, the crystal, and the antenna. A wireless communicationdevice can include the packaged radio frequency module. A system boardassembly can include the packaged radio frequency module.

Another aspect of this disclosure is a packaged radio frequency modulefor use in a wireless communication device. The packaged radio frequencymodule includes a radio frequency shielding structure extending above apackage substrate, a first integrated circuit die supported by thepackage substrate and in an interior of the radio frequency shieldingstructure, an antenna supported by the package substrate external to theradio frequency shielding structure, and a second integrated circuit diesupported by the package substrate. The package substrate is disposedbetween the first integrated circuit die and the second integratedcircuit die.

The first integrated circuit die can implement at least a portion of aradio frequency front end including a radio frequency power amplifierand the second integrated circuit die can implement at least a portionof a radio frequency baseband subsystem. The packaged radio frequencymodule can include an overmold enclosing the first integrated circuitdie and the antenna. A wireless communication device can include thepackaged radio frequency module. A system board assembly can include thepackaged radio frequency module.

Another aspect of this disclosure is a packaged radio frequency modulefor use in a wireless communication device. The packaged radio frequencymodule includes a radio frequency shielding structure extending above apackage substrate; a first wireless device component supported by thepackage substrate and in an interior of the radio frequency shieldingstructure; an antenna supported by the package substrate external to theradio frequency shielding structure; and a second wireless devicecomponent supported by and spaced from the package substrate, the firstwireless device component between the second wireless device componentand a first surface of the package substrate, at least a firstoverhanging portion of the second wireless device component extendingbeyond at least a portion of the periphery of the first wireless devicecomponent.

The first wireless device component can include a radio frequencycomponent. The packaged radio frequency module can include an overmoldenclosing the first wireless device component, the antenna, and thesecond wireless device component. A wireless communication device caninclude the packaged radio frequency module. A system board assembly caninclude the packaged radio frequency module.

Another aspect of this disclosure is a packaged radio frequency modulefor use in a wireless communication device. The packaged radio frequencymodule includes a multi-layer substrate having a first side and a secondside opposite to the first side, the multi-layer substrate including aground plane; an antenna on the first side of the multi-layer substrate;a first die including at least a radio frequency component, the firstdie disposed on the second side of the multi-layer substrate such thatthe ground plane is positioned between the antenna and the radiofrequency component; a crystal disposed on the second side of themulti-layer substrate such that the first die is positioned between thecrystal and the second side of the multi-layer substrate; and conductivefeatures disposed around the radio frequency component and electricallyconnected to the ground plane.

The packaged radio frequency module can include an overmold enclosingthe first die and the crystal. The first die can include amicroprocessor. The conductive features and the ground plane can beconfigured to provide shielding for the radio frequency component. Awireless communication device can include the packaged radio frequencymodule. A system board assembly can include the packaged radio frequencymodule.

Another aspect of this disclosure is a radio frequency module thatincludes a multi-layer substrate having a first side and a second sideopposite to the first side, the multi-layer substrate including a groundplane; an antenna on the first side of the multi-layer substrate; afirst die including at least radio frequency receiver circuitry disposedon the second side of the multi-layer substrate such that the groundplane is positioned between the antenna and the radio frequency receivercircuitry; conductive features disposed around the radio frequencyreceiver circuitry and electrically connected to the ground plane; and astacked filter assembly configured as a filter circuit that is incommunication with the radio frequency receiver circuitry, the stackedfilter assembly disposed on the second side of the multi-layersubstrate.

The first die can include a microprocessor. The conductive features andthe ground plane can be configured to provide shielding for the radiofrequency receiver circuitry. The stacked filter assembly can include aplurality of passive components. Each passive component of the pluralityof passive components can be packaged as a surface mount device. Atleast one passive component can be in direct communication with thesecond side of the multi-layer substrate and at least another passivecomponent can be supported above the second side of the multi-layersubstrate by the at least one passive component that is in the directcommunication with the second side of the multi-layer substrate. Theradio frequency module can include an overmold enclosing the first dieand the stacked filter assembly. A wireless communication device caninclude the packaged radio frequency module. A system board assembly caninclude the packaged radio frequency module.

Another aspect of this disclosure is a radio frequency module thatincludes a multi-layer substrate having a first side and a second sideopposite to the first side, the multi-layer substrate including a groundplane; an antenna on the first side of the multi-layer substrate; afirst integrated circuit die implementing a radio frequency poweramplifier, the first integrated circuit die disposed on the second sideof the multi-layer substrate such that the ground plane is positionedbetween the antenna and the radio frequency power amplifier; conductivefeatures disposed around at least the radio frequency power amplifierand electrically connected to the ground plane; and a second integratedcircuit die disposed on the first side of the multi-layer substrate.

At least a portion of a radio frequency front end can include the radiofrequency power amplifier. The conductive features and the ground planecan be configured to provide shielding for the radio frequency poweramplifier. The second integrated circuit die can implement at least aportion of a radio frequency baseband subsystem. The radio frequencymodule can include an overmold enclosing the second integrated circuitdie and the antenna. A wireless communication device can include thepackaged radio frequency module. A system board assembly can include thepackaged radio frequency module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate; and a crystal assembly configured to provide aclock signal for use in the first die, the crystal assembly supported bythe substrate and disposed between the first die and the substrate, thecrystal assembly including a crystal, a conductive pillar, and anenclosure configured to enclose the crystal, the conductive pillarformed at least partially within a side of the enclosure and extendingfrom a top surface to a bottom surface of the enclosure.

The first die can include at least a microprocessor and one or more ofradio frequency transmitter circuitry and radio frequency receivercircuitry. The clock signal can be provided for use in the at least oneof the microprocessor and the one or more of the radio frequencytransmitter circuitry and the radio frequency receiver circuitry. Thecrystal assembly can further include an input terminal configured toreceive a first signal and an output terminal configured to output theclock signal, the conductive pillar configured to conduct a third signaldistinct from the first signal and the clock signal. The packaged modulecan include an overmold enclosing the first die and the crystalassembly. A wireless communication device can include the packagedmodule. A system board assembly can include the packaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate; and a crystal assembly configured to provide aclock signal for use in the first die, the crystal assembly supported bythe substrate, the first die disposed between the crystal assembly andthe substrate, the crystal assembly including a crystal, a conductivepillar, and an enclosure configured to enclose the crystal, theconductive pillar formed at least partially within a side of theenclosure and extending from a top surface to a bottom surface of theenclosure.

The first die can include at least a microprocessor and one or more ofradio frequency transmitter circuitry and radio frequency receivercircuitry. The clock signal can be provided for use in the at least oneof the microprocessor and the one or more of the radio frequencytransmitter circuitry and the radio frequency receiver circuitry. Thecrystal assembly can further include an input terminal configured toreceive a first signal and an output terminal configured to output theclock signal, the conductive pillar configured to conduct a third signaldistinct from the first signal and the clock signal. The packaged modulecan include an overmold enclosing the first die and the crystalassembly. A wireless communication device can include the packagedmodule. A system board assembly can include the packaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate; a crystal assembly configured to provide aclock signal for use the first die, the crystal assembly supported bythe substrate and disposed between the first die and the substrate, thecrystal assembly including a crystal, a conductive pillar, and anenclosure configured to enclose the crystal, the conductive pillarformed at least partially within a side of the enclosure and extendingfrom a top surface to a bottom surface of the enclosure; and a stackedfilter assembly supported by the substrate and, the stacked filterassembly including a plurality of passive components, at least onepassive component being in direct communication with the substrate andat least another passive component supported above the substrate by theat least one passive component that is in the direct communication withthe substrate.

The first die can include at least one of the microprocessor and theradio frequency receiver circuitry. The clock signal can be provided foruse in the at least one of the microprocessor and the radio frequencyreceiver circuitry. The stacked filter assembly can be configured as afilter circuit that is in communication with the radio frequencyreceiver circuitry. The crystal assembly can further include an inputterminal configured to receive a first signal and an output terminalconfigured to output the clock signal, the conductive pillar configuredto conduct a third signal distinct from the first signal and the clocksignal. Each passive component of the plurality of passive componentscan be packaged as a surface mount device. The packaged module caninclude an overmold enclosing the first die, the crystal assembly, andthe stacked filter assembly. A wireless communication device can includethe packaged module. A system board assembly can include the packagedmodule.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a firstintegrated circuit die supported by a substrate; a crystal assemblyconfigured to provide a clock signal to the first integrated circuitdie, the crystal assembly supported by the substrate and disposedbetween the first integrated circuit die and the substrate, the crystalassembly including a crystal, a conductive pillar, and an enclosureconfigured to enclose the crystal, the conductive pillar formed at leastpartially within a side of the enclosure and extending from a topsurface to a bottom surface of the enclosure; and a second integratedcircuit die supported by the substrate, the substrate disposed betweenthe first integrated circuit die and the second integrated circuit die.

The first integrated circuit die can implement at least a portion of aradio frequency baseband subsystem. The clock signal can be provided forthe at least a portion of the radio frequency baseband subsystem. Thecrystal assembly can further include an input terminal configured toreceive a first signal and an output terminal configured to output theclock signal, the conductive pillar configured to conduct a third signaldistinct from the first signal and the clock signal. The secondintegrated circuit die can implement at least a portion of a radiofrequency front end including a radio frequency power amplifier. Thepackaged module can include an overmold enclosing the first integratedcircuit die and the crystal assembly. A wireless communication devicecan include the packaged module. A system board assembly can include thepackaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a firstwireless device component supported by a substrate; a second wirelessdevice component supported by and spaced from the substrate, the firstwireless device component between the second wireless device componentand the substrate, at least a first overhanging portion of the secondwireless device component extending beyond at least a portion of theperiphery of the first wireless device component; and a crystal assemblysupported by the substrate and disposed between the at least the firstoverhanging portion of the second wireless device component and thesubstrate, the crystal assembly including a crystal, a conductivepillar, and an enclosure configured to enclose the crystal, theconductive pillar formed at least partially within a side of theenclosure and extending from a top surface to a bottom surface of theenclosure.

The crystal assembly can further include an input terminal configured toreceive a first signal and an output terminal configured to output asecond signal, the conductive pillar configured to conduct a thirdsignal distinct from the first and second signals. The packaged modulecan include an overmold enclosing the first wireless device component,the second wireless device component, and the crystal assembly. Awireless communication device can include the packaged module. A systemboard assembly can include the packaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate; a stacked filter assembly supported by thesubstrate, the stacked filter assembly including a plurality of passivecomponents, at least one passive component being in direct communicationwith the substrate and at least another passive component supportedabove the substrate by the at least one passive component that is in thedirect communication with the substrate; and a crystal supported by thesubstrate, the first die disposed between the crystal and the substrate.

The first die can include at least a microprocessor and radio frequencyreceiver circuitry. The stacked filter assembly can be configured as afilter circuit that is in communication with the radio frequencyreceiver circuitry. Each passive component of the plurality of passivecomponents can be packaged as a surface mount device. The packagedmodule can include an overmold enclosing the first die, the stackedfilter assembly, and the crystal. A wireless communication device caninclude the packaged module. A system board assembly can include thepackaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate; a stacked filter assembly supported by thesubstrate and including a plurality of passive components, at least onepassive component being in direct communication with the substrate andat least another passive component supported above the substrate by theat least one passive component that is in the direct communication withthe substrate; and a crystal supported by the substrate and disposedbetween the first die and the substrate.

The first die can include at least a microprocessor and radio frequencyreceiver circuitry. The stacked filter assembly can be configured as afilter circuit that is in communication with the radio frequencyreceiver circuitry. Each passive component of the plurality of passivecomponents can be packaged as a surface mount device. The packagedmodule can include an overmold enclosing the first die, the stackedfilter assembly, and the crystal. A wireless communication device caninclude the packaged module. A system board assembly can include thepackaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate; a stacked filter assembly supported by thesubstrate, the stacked filter assembly including a plurality of passivecomponents, at least one passive component being in direct communicationwith the substrate and at least another passive component supportedabove the substrate by the at least one passive component that is in thedirect communication with the substrate; and a second die supported bythe substrate, the substrate disposed between the first die and thesecond die.

The first die can include at least a microprocessor and radio frequencyreceiver circuitry. The stacked filter assembly can be configured as afilter circuit that is in communication with the radio frequencyreceiver circuitry. The second die can implement at least a portion of aradio frequency front end including a radio frequency power amplifier.Each passive component of the plurality of passive components can bepackaged as a surface mount device. The packaged module can include anovermold enclosing the first die and the stacked filter assembly. Awireless communication device can include the packaged module. A systemboard assembly can include the packaged module.

Another aspect of this disclosure is a packaged module for a radiofrequency wireless device. The packaged module includes a first wirelessdevice component supported by a substrate and including at least amicroprocessor and radio frequency receiver circuitry; a second wirelessdevice component supported by and spaced from the substrate, the firstwireless device component between the second wireless device componentand the substrate, at least a first overhanging portion of the secondwireless device component extending beyond at least a portion of theperiphery of the first wireless device component; and a stacked filterassembly supported by the substrate and configured as a filter circuitthat is in communication with the radio frequency receiver circuitry,the stacked filter assembly including a plurality of passive components,at least one passive component being in direct communication with thesubstrate, the stacked filter assembly disposed between the at least afirst overhanging portion and the substrate.

Each passive component of the plurality of passive components can bepackaged as a surface mount device. At least another passive componentcan be supported above the substrate by the at least one passivecomponent that is in the direct communication with the substrate. Thepackaged module can include an overmold enclosing the first wirelessdevice component, the second wireless device component, and the stackedfilter assembly. A wireless communication device can include thepackaged module. A system board assembly can include the packagedmodule.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a first diesupported by a substrate and including at least one of a microprocessor,radio frequency transmitter circuitry, and radio frequency receivercircuitry; a crystal configured to provide a timing signal for use inthe first die, the crystal supported by the substrate and disposedbetween the first die and the substrate; and a second die supported bythe substrate and implementing at least a portion of a radio frequencyfront end including a radio frequency power amplifier, the substratedisposed between the first die and the second die.

The packaged module can include an overmold enclosing the first die andthe crystal. A wireless communication device can include the packagedmodule. A system board assembly can include the packaged module.

Another aspect of this disclosure is a packaged module for use in aradio frequency wireless device. The packaged module includes a firstwireless device component supported by a substrate; a second wirelessdevice component supported by and spaced from the substrate andimplementing at least a portion of a radio frequency baseband subsystem,the first wireless device component positioned between the secondwireless device component and the substrate, at least a firstoverhanging portion of the second wireless device component extendingbeyond at least a portion of the periphery of the first wireless devicecomponent; and a third wireless device component supported by thesubstrate and implementing at least a portion of a radio frequency frontend including a radio frequency power amplifier, the substrate disposedbetween the second wireless device component and the third wirelessdevice component.

The packaged module can include an overmold enclosing the first wirelessdevice component and the second wireless device component. A wirelesscommunication device can include the packaged module. A system boardassembly can include the packaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a firstwireless device component supported by a substrate; a second wirelessdevice component supported by and spaced from the substrate, the firstwireless device component between the second wireless device componentand the substrate, at least a first overhanging portion of the secondwireless device component extending beyond at least a portion of theperiphery of the first wireless device component; and a crystalsupported by the substrate, the first wireless device component and thesecond wireless device component disposed between the crystal and thesubstrate.

The packaged module can include an overmold enclosing the first wirelessdevice component, the second wireless device component, and the crystal.A wireless communication device can include the packaged module. Asystem board assembly can include the packaged module.

Another aspect of this disclosure is a packaged module for use in awireless communication device. The packaged module includes a firstwireless device component supported by a substrate; a second wirelessdevice component supported by and spaced from the substrate, the firstwireless device component positioned between the second wireless devicecomponent and the substrate, at least a first overhanging portion of thesecond wireless device component extending beyond at least a portion ofthe periphery of the first wireless device component; and a crystalsupported by the substrate, the crystal disposed within the at least thefirst overhanging portion of the second wireless device component andbetween the second wireless device component and the substrate.

The packaged module can include an overmold enclosing the first wirelessdevice component, the second wireless device component, and the crystal.A wireless communication device can include the packaged module. Asystem board assembly can include the packaged module.

Another aspect of this disclosure is a packaged radio frequency modulefor use in a wireless communication device. The packaged radio frequencymodule includes a radio frequency shielding structure extending above apackage substrate; a first die supported by the package substrate and inan interior of the radio frequency shielding structure, the first dieincluding a radio frequency component; an antenna supported by thepackage substrate external to the radio frequency shielding structure;and a crystal assembly supported by the package substrate and disposedbetween the first die and the package substrate, the crystal assemblyincluding a crystal, a conductive pillar, and an enclosure configured toenclose the crystal, the conductive pillar formed at least partiallywithin a side of the enclosure and extending from a top surface to abottom surface of the enclosure.

The packaged radio frequency module can include an overmold enclosingthe first die, the crystal assembly, and the antenna. The crystalassembly can further include an input terminal configured to receive afirst signal, an output terminal configured to output a second signal,and the conductive pillar is configured to conduct a third signaldistinct from the first and second signals. A wireless communicationdevice can include the packaged radio frequency module. A system boardassembly can include the packaged radio frequency module.

Another aspect of this disclosure is a packaged radio frequency modulefor use in a wireless communication device. The packaged radio frequencymodule includes a radio frequency shielding structure extending above apackage substrate; a first die supported by the package substrate and inan interior of the radio frequency shielding structure, the first dieincluding radio frequency receiver circuitry; an antenna supported bythe package substrate external to the radio frequency shieldingstructure; and a stacked filter assembly supported by the packagesubstrate and configured as a filter circuit that is in communicationwith the radio frequency receiver circuitry, the stacked filter assemblyincluding a plurality of passive components, at least one passivecomponent being in direct communication with the package substrate andat least another passive component supported above the package substrateby the at least one passive component that is in the directcommunication with the package substrate.

Each passive component of the plurality of passive components can bepackaged as a surface mount device. The packaged radio frequency modulecan include an overmold enclosing the first die, the stacked filterassembly, and the antenna. The wireless communication device can includethe packaged radio frequency module. A system board assembly can includethe packaged radio frequency module

Another aspect of this disclosure is a packaged radio frequency modulefor use in a wireless communication device. The packaged radio frequencymodule includes a multi-layer substrate having a first side and a secondside opposite to the first side, the multi-layer substrate including aground plane; an antenna on the first side of the multi-layer substrate;a first die including at least a radio frequency component, the firstdie disposed on the second side of the multi-layer substrate such thatthe ground plane is positioned between the antenna and the radiofrequency component; a crystal disposed on the second side of themulti-layer substrate such that the crystal is positioned between thefirst die and the second side of the multi-layer substrate; andconductive features disposed around the radio frequency component andelectrically connected to the ground plane.

The first die can include a microprocessor. The conductive features andthe ground plane can be configured to provide shielding for the radiofrequency component. The packaged radio frequency module can include anovermold enclosing the first die and the crystal. A wirelesscommunication device can include the packaged radio frequency module. Asystem board assembly can include the packaged radio frequency module.

Another aspect of this disclosure is a radio frequency module thatincludes a multi-layer substrate having a first side and a second sideopposite to the first side, the multi-layer substrate including a groundplane; an antenna on the first side of the multi-layer substrate; afirst die including at least a radio frequency component disposed on thesecond side of the multi-layer substrate such that the ground plane ispositioned between the antenna and the radio frequency component;conductive features disposed around the radio frequency component andelectrically connected to the ground plane; and a crystal assemblydisposed on the second side of the multi-layer substrate such that thecrystal assembly is positioned between the first die and the second sideof the multi-layer substrate, the crystal assembly including a crystal,a conductive pillar, and an enclosure configured to enclose the crystal,the conductive pillar formed at least partially within a side of theenclosure and extending from a top surface to a bottom surface of theenclosure.

The conductive features and the ground plane can be configured toprovide shielding for the radio frequency component. The crystalassembly can further include an input terminal configured to receive afirst signal, an output terminal configured to output a second signal,the conductive pillar configured to conduct a third signal distinct fromthe first and second signals. The packaged radio frequency module caninclude an overmold enclosing the first die and the crystal assembly. Awireless communication device can include the radio frequency module. Asystem board assembly can include the radio frequency module.

Another aspect of this disclosure is a radio frequency module thatincludes a multi-layer substrate including a ground plane and having afirst side and a second side opposite to the first side, an antenna onthe first side of the multi-layer substrate, a radio frequency componentdisposed on the second side of the multi-layer substrate such that theground plane is positioned between the antenna and the radio frequencycomponent, a first wireless device component spaced from the second sideof the multi-layer substrate, and conductive features disposed aroundthe radio frequency component and electrically connected to the groundplane. The radio frequency component is positioned between the firstwireless device component and the second side of the multi-layersubstrate, at least a first overhanging portion of the first wirelessdevice component extends beyond at least a portion of the periphery ofthe radio frequency component.

The conductive features and the ground plane can be configured toprovide shielding for the radio frequency component. The radio frequencymodule can include an overmold enclosing the radio frequency componentand the first wireless device component. A wireless communication devicecan include the radio frequency module. A system board assembly caninclude the radio frequency module.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment. Thus, the any ofinnovations may be embodied or carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught herein withoutnecessarily achieving other advantages as may be taught or suggestedherein.

The present application hereby incorporates by reference the entiredisclosures of U.S. Provisional Patent Application No. 62/440,241,titled FRONT END SYSTEMS, filed Dec. 29, 2016; U.S. Provisional PatentApplication No. 62/480,002, titled FRONT END SYSTEMS AND RELATEDDEVICES, INTEGRATED CIRCUITS, MODULES, AND METHODS, filed Mar. 31, 2017;U.S. Provisional Patent Application No. 62/570,549, titled FRONT ENDSYSTEMS AND RELATED DEVICES, INTEGRATED CIRCUITS, MODULES, AND METHODS,filed Oct. 10, 2017; U.S. Provisional Patent Application No. 62/571,409,titled FRONT END SYSTEMS AND RELATED DEVICES, INTEGRATED CIRCUITS,MODULES, AND METHODS, filed Oct. 12, 2017; U.S. Provisional PatentApplication No. 62/594,179, titled FRONT END SYSTEMS AND RELATEDDEVICES, INTEGRATED CIRCUITS, MODULES, AND METHODS, filed Dec. 4, 2017;and U.S. Provisional Patent Application No. 62/595,935, titled FRONT ENDSYSTEMS AND RELATED DEVICES, INTEGRATED CIRCUITS, MODULES, AND METHODS,filed Dec. 7, 2017.

The present application also hereby incorporates by reference the entiredisclosures of: U.S. patent application Ser. No. 15/585,631, titledSHIELDED RADIO FREQUENCY COMPONENT WITH INTEGRATED ANTENNA, filed May 5,2017; U.S. patent application Ser. No. 15/389,097, titled IMPEDANCETRANSFORMATION CIRCUIT FOR AMPLIFIER, filed Dec. 22, 2016; U.S. patentapplication Ser. No. 15/458,423, titled APPARATUS AND METHODS FOROVERLOAD PROTECTION OF LOW NOISE AMPLIFIERS, filed Mar. 14, 2017; U.S.patent application Ser. No. 15/393,590, titled APPARATUS AND METHODS FORELECTRICAL OVERSTRESS PROTECTION, filed Dec. 29, 2016; U.S. patentapplication Ser. No. 15/474,905, titled MULTI-MODE STACKED AMPLIFIER,filed Mar. 30, 2017; U.S. patent application Ser. No. 15/584,463, titledAPPARATUS AND METHODS FOR POWER AMPLIFIERS WITH AN INJECTION-LOCKEDOSCILLATOR DRIVER STAGE, filed May 2, 2017; U.S. patent application Ser.No. 15/490,346, titled SELECTIVE SHIELDING OF RADIO FREQUENCY MODULES,filed Apr. 18, 2017; U.S. patent application Ser. No. 15/490,349, titledMETHODS FOR SELECTIVELY SHIELDING RADIO FREQUENCY MODULES, filed Apr.18, 2017; U.S. patent application Ser. No. 15/490,436, titledSELECTIVELY SHIELDING RADIO FREQUENCY MODULE WITH MULTI-LAYER ANTENNA,filed Apr. 18, 2017; U.S. patent application Ser. No. 15/489,506, titledRADIO FREQUENCY SYSTEM-IN-PACKAGE INCLUDING A STACKED SYSTEM-ON-CHIP,filed Apr. 17, 2017; U.S. patent application Ser. No. 15/489,532, titledSYSTEM IN PACKAGE WITH VERTICALLY ARRANGED RADIO FREQUENCY COMPONENTRY,filed Apr. 17, 2017; U.S. patent application Ser. No. 15/489,607, titledREDUCED FORM FACTOR RADIO FREQUENCY SYSTEM-IN-PACKAGE, filed Apr. 17,2017; U.S. patent application Ser. No. 15/489,631, titled CRYSTALPACKAGING WITH CONDUCTIVE PILLARS, filed Apr. 17, 2017; U.S. patentapplication Ser. No. 15/489,563, titled SURFACE MOUNT DEVICE STACKINGFOR REDUCED FORM FACTOR, filed Apr. 17, 2017; U.S. patent applicationSer. No. 15/489,528, titled RADIO FREQUENCY SYSTEM-IN-PACKAGE WITHSTACKED CLOCKING CRYSTAL, filed Apr. 17, 2017; U.S. patent applicationSer. No. 15/654,050, titled IMPEDANCE TRANSFORMATION CIRCUIT ANDOVERLOAD PROTECTION FOR LOSE NOISE AMPLIFIER, filed Jul. 19, 2017; U.S.patent application Ser. No. 15/855,065, titled RADIO FREQUENCYAMPLIFIERS WITH INJECTION-LOCKED OSCILLATOR DRIVER STAGE AND A STACKEDOUTPUT STAGE, filed Dec. 27, 2017; and U.S. Provisional PatentApplication No. 62/573,524, titled RADIO FREQUENCY MODULES, filed Oct.17, 2017.

Any combination of features described in the patent applications thatare incorporated by reference can be implemented in combination with oneor more aspects described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a schematic block diagram of one example of a frontend system.

FIG. 1B illustrates a schematic block diagram of another example of afront end system.

FIG. 2 is a schematic block diagram of a front end system that includesa multi-mode power amplifier and a low noise amplifier with magneticallycoupled inductors according to an embodiment.

FIG. 3 is a schematic block diagram of a front end system that includesa power amplifier with an injection-locked oscillator driver stage and alow noise amplifier with magnetically coupled inductors according to anembodiment.

FIG. 4 is a schematic block diagram of a front end system that includesan antenna-side switch, a power amplifier, a low noise amplifier, and anoverload protection circuit according to an embodiment.

FIG. 5 is a schematic block diagram of a front end system that includesa radio frequency switch, a low noise amplifier, an overload protectioncircuit, and a multi-mode power amplifier according to an embodiment.

FIG. 6 is a schematic block diagram of a front end integrated circuitthat includes an overstress protection circuit and a low noise amplifierwith magnetically coupled inductors according to an embodiment.

FIG. 7 is a schematic block diagram of a front end integrated circuitthat includes an overstress protection circuit and a low noise amplifiersystem according to an embodiment.

FIG. 8 is a schematic block diagram of a front end integrated circuitthat includes an overstress protection circuit and a multi-mode poweramplifier according to an embodiment.

FIG. 9 is a schematic block diagram of a front end integrated circuitthat includes an overstress protection circuit and a power amplifierthat includes an injection-locked oscillator driver stage according toan embodiment.

FIG. 10 is a schematic diagram of a packaged module that includes a lownoise amplifier with magnetically coupled inductors within a radiofrequency shielding structure and an antenna external to the radiofrequency shielding structure according to an embodiment.

FIG. 11 is a schematic diagram of a packaged module that includes a lownoise amplifier and an overload protection circuit within a radiofrequency shielding structure and an antenna external to the radiofrequency shielding structure according to an embodiment.

FIG. 12 is a schematic diagram of a packaged module that includes amulti-mode power amplifier within a radio frequency shielding structureand an antenna external to the radio frequency shielding structureaccording to an embodiment.

FIG. 13 is a schematic diagram of a packaged module that includes aninjection-locked oscillator driver stage within a radio frequencyshielding structure and an antenna external to the radio frequencyshielding structure according to an embodiment.

FIG. 14 is a schematic diagram of a packaged module that includes anoverstress protection circuit within a radio frequency shieldingstructure and an antenna external to the radio frequency shieldingstructure according to an embodiment.

FIG. 15A is a cross section of a packaged module that includes a groundplane between an antenna and a front end integrated circuit according toan embodiment.

FIGS. 15B to 15F are example cross sections of the packaged module ofFIG. 15A that include various front end integrated circuits according tocertain embodiments. In FIG. 15B, the front end integrated circuitincludes a low noise amplifier with magnetically coupled inductors. InFIG. 15C, the front end integrated circuit includes a low noiseamplifier and an overload protection circuit. In FIG. 15D, the front endintegrated circuit includes a multi-mode power amplifier. In FIG. 15E,the front end integrated circuit includes a power amplifier thatincludes an injection-locked oscillator driver stage. In FIG. 15F, thefront end integrated circuit includes an overstress protection circuit.

FIG. 16 is a cross section of a packaged module that includes anintegrated circuit, a crystal vertically integrated with the integratedcircuit, and an other integrated circuit that includes a low noiseamplifier with magnetically coupled inductors according to anembodiment.

FIG. 17 is a cross section of a packaged module that includes anintegrated circuit, a crystal vertically integrated with the integratedcircuit, and an other integrated circuit that includes a low noiseamplifier and an overload protection circuit according to an embodiment.

FIG. 18 is a cross section of a packaged module that an integratedcircuit, a crystal vertically integrated with the integrated circuit,and an other integrated circuit that includes a multi-mode poweramplifier according to an embodiment.

FIG. 19 is a cross section of a packaged module that includes anintegrated circuit, a crystal vertically integrated with the integratedcircuit, and an other integrated circuit that includes a power amplifierwith an injection-locked oscillator driver stage according to anembodiment.

FIG. 20 is a cross section of a packaged module that includes anintegrated circuit, a crystal vertically integrated with the integratedcircuit, and an other integrated circuit that includes an overstressprotection circuit according to an embodiment.

FIG. 21 is a cross section of a packaged module that includes anintegrated circuit, a crystal assembly under the integrated circuit, andan other integrated circuit that includes a low noise amplifier withmagnetically coupled inductors according to an embodiment.

FIG. 22 is a cross section of a packaged module that includes anintegrated circuit, a crystal assembly under the integrated circuit, andan other integrated circuit that includes a low noise amplifier and anoverload protection circuit according to an embodiment.

FIG. 23 is a cross section of a packaged module that an integratedcircuit, a crystal assembly under the integrated circuit, and an otherintegrated circuit that includes a multi-mode power amplifier accordingto an embodiment.

FIG. 24 is a cross section of a packaged module that includes anintegrated circuit, a crystal assembly under the integrated circuit, andan other integrated circuit that includes a power amplifier with aninjection-locked oscillator driver stage according to an embodiment.

FIG. 25 is a cross section of a packaged module that includes anintegrated circuit, a crystal assembly under the integrated circuit, andan other integrated circuit that includes an overstress protectioncircuit according to an embodiment.

FIG. 26 is a block diagram of a packaged module that includes a stackedfilter assembly and a low noise amplifier with magnetically coupledinductors according to an embodiment.

FIG. 27 is a block diagram of a packaged module that includes a stackedfilter assembly and a low noise amplifier and an overload protectioncircuit according to an embodiment.

FIG. 28 is a block diagram of a packaged module that includes a stackedfilter assembly and a multi-mode power amplifier according to anembodiment.

FIG. 29 is a block diagram of a packaged module that includes a stackedfilter assembly and a power amplifier with an injection-lockedoscillator driver stage according to an embodiment.

FIG. 30 is a block diagram of a packaged module that includes a stackedfilter assembly an overstress protection circuit according to anembodiment.

FIG. 31 is a schematic diagram of one example of an Internet of things(IoT) network.

FIG. 32A is a schematic diagram of one example of an IoT-enabled watch.

FIG. 32B is a schematic diagram of one example of a front end system foran IoT-enabled object.

FIG. 33A is a schematic diagram of one example of IoT-enabled vehicles.

FIG. 33B is a schematic diagram of another example of a front end systemfor an IoT-enabled object.

FIG. 34A is a schematic diagram of one example of IoT-enabled industrialequipment.

FIG. 34B is a schematic diagram of another example of a front end systemfor an IoT-enabled object.

FIG. 35A is a schematic diagram of one example of an IoT-enabled lock.

FIG. 35B is a schematic diagram of one example of a circuit board forthe IoT-enabled lock of FIG. 35A.

FIG. 36A is a schematic diagram of one example of an IoT-enabledthermostat.

FIG. 36B is a schematic diagram of one example of a circuit board forthe IoT-enabled thermostat of FIG. 36A.

FIG. 37A is a schematic diagram of one example of IoT-enabled light.

FIG. 37B is a schematic diagram of one example of a circuit board forthe IoT-enabled light of FIG. 37A.

FIG. 38A illustrates a schematic block diagram of one example of a radiofrequency system.

FIG. 38B illustrates a schematic block diagram of another example of aradio frequency system.

FIG. 38C illustrates a schematic block diagram of another example of aradio frequency system.

FIG. 38D illustrates a schematic block diagram of another example of aradio frequency system.

FIG. 38E illustrates a schematic block diagram of another example of aradio frequency system.

FIG. 38F illustrates a schematic block diagram of another example of aradio frequency system.

FIG. 39A is a schematic diagram of one example of a wirelesscommunication device.

FIG. 39B is a schematic diagram of another example of a wirelesscommunication device.

FIG. 39C is a schematic diagram of another example of a wirelesscommunication device.

FIG. 40A is a schematic diagram of a low noise amplifier that includesfield effect transistors and an impedance transformation circuitaccording to an embodiment.

FIG. 40B is a schematic diagram of a low noise amplifier that includesbipolar transistors an impedance transformation circuit according to anembodiment.

FIG. 40C is a schematic diagram of a low noise amplifier that includes abipolar transistor, a field effect transistor, and an impedancetransformation circuit according to an embodiment.

FIG. 40D is a schematic diagram of a low noise amplifier that includesan amplification circuit and an impedance transformation circuitaccording to an embodiment.

FIG. 41A is a schematic diagram of a low noise amplifier systemaccording to an embodiment.

FIG. 41B is a schematic diagram of a low noise amplifier systemaccording to an embodiment.

FIG. 41C is a schematic diagram of a low noise amplifier systemaccording to an embodiment.

FIG. 41D is a schematic diagram of a low noise amplifier system thatincludes an illustrative bias circuit according to an embodiment.

FIG. 41E is a schematic diagram of a low noise amplifier system with abias and matching circuit according to an embodiment.

FIG. 41F is a schematic diagram of a low noise amplifier system thatincludes an illustrative bias and matching circuit according to anembodiment.

FIG. 42 is a Smith chart corresponding to the passive impedance networkof FIG. 41A.

FIG. 43 illustrates a physical layout of magnetically coupled inductorsof a low noise amplifier according to an embodiment.

FIG. 44 is a schematic diagram of a low noise amplifier (LNA) systemwith overload protection according to one embodiment.

FIG. 45A is a schematic diagram of an LNA system with overloadprotection according to another embodiment.

FIG. 45B is a schematic diagram of an LNA system with overloadprotection according to another embodiment.

FIG. 46A is a schematic diagram of an LNA and a detector according toone embodiment.

FIG. 46B is a schematic diagram of an LNA and a detector according toanother embodiment.

FIG. 47 is a schematic diagram of an error amplifier according to oneembodiment.

FIG. 48A is a schematic diagram of a limiter enable circuit according toone embodiment.

FIG. 48B is a schematic diagram of a limiter enable circuit according toanother embodiment.

FIG. 49 is a schematic diagram of an LNA system with overload protectionaccording to another embodiment.

FIG. 50 is a schematic diagram of an example power amplifier system.

FIG. 51 is a graph illustrating a relationship between peak outputvoltage and direct current (DC) current for different conduction anglesof a stacked amplifier at a fixed output power level.

FIG. 52A illustrates a stacked amplifier with three transistors in thestack and a maximum allowable voltage swing of the stacked amplifier fora supply voltage.

FIG. 52B illustrates a stacked amplifier with two transistors in thestack and a maximum allowable voltage swing of the stacked amplifier forthe same supply voltage as FIG. 52A.

FIG. 53A is a schematic diagram of a triple-stacked power amplifierarchitecture with conceptual biasing illustrated for two modes ofoperation according to an embodiment.

FIG. 53B is a schematic diagram of the triple-stacked power amplifierarchitecture of FIG. 53A with conceptual biasing illustrated for adifferent mode of operation.

FIG. 53C is a schematic diagram of a power amplifier system withconceptual biasing illustrated for a first mode of operation accordingto an embodiment.

FIG. 53D is a schematic diagram of the power amplifier system of FIG.53C with conceptual biasing illustrated for a second mode of operation.

FIG. 54A is a schematic diagram of a stacked amplifier and a biascircuit in a first mode according to an embodiment.

FIG. 54B is a schematic diagram of the stacked amplifier and the biascircuit of FIG. 54A in a second mode according to an embodiment.

FIG. 55A is a schematic diagram of a stacked amplifier with bipolartransistors and a bias circuit in a first mode according to anembodiment.

FIG. 55B is a schematic diagram of the stacked amplifier and the biascircuit of FIG. 55A in a second mode of operation according to anembodiment.

FIG. 56A is a schematic diagram of a stacked amplifier with fourtransistors in the stack and a bias circuit in a first mode according toan embodiment.

FIG. 56B is a schematic diagram of the stacked amplifier and the biascircuit of FIG. 56A in a different mode.

FIG. 56C is a schematic diagram of the stacked amplifier and the biascircuit of FIG. 56A in a different mode than FIGS. 56A and 56B.

FIG. 57A is a schematic diagram of a stacked amplifier with twotransistors in the stack and a bias circuit in a first mode according toan embodiment.

FIG. 57B is a schematic diagram of the stacked amplifier and the biascircuit of FIG. 57A in a second mode according to an embodiment.

FIG. 58A is a schematic diagram of a triple-stacked power amplifierarchitecture having a switch to selectively provide an input signal todifferent transistors in the triple-stack according to an embodiment.

FIG. 58B is a schematic diagram of the triple-stacked power amplifierarchitecture of FIG. 58A with the conceptual biasing illustrated for adifferent mode of operation according to an embodiment.

FIG. 59 is a schematic diagram of one example of a power amplifiersystem.

FIG. 60 is a schematic diagram of one example of a multi-mode poweramplifier.

FIGS. 61A, 61B, and 61C show graphs of simulation results for oneimplementation of the multi-mode power amplifier of FIG. 60. FIG. 61Ashows a graph of power added efficiency (PAE) and gain versus outputpower. FIG. 61B shows a graph of current consumption versus outputpower. FIG. 61C shows a graph of power level versus output power.

FIG. 62A is a schematic diagram of a multi-mode power amplifieraccording to one embodiment.

FIG. 62B is a schematic diagram of a multi-mode power amplifieraccording to another embodiment.

FIG. 63 is a schematic diagram of an injection-locked oscillator driverstage according to one embodiment.

FIG. 64 is a schematic diagram of one example of an integrated circuitthat can include one or more electrical overstress (EOS) protectioncircuits.

FIG. 65A is a schematic diagram of one example of a module that caninclude one or more EOS protection circuits.

FIG. 65B is a cross section of the module of FIG. 65A taken along thelines 65B-65B.

FIG. 65C is a cross section of a module according to another embodiment.

FIG. 66A is a schematic diagram of an integrated circuit (IC) interfaceincluding an EOS protection circuit according to one embodiment.

FIG. 66B is a schematic diagram of an IC interface including an EOSprotection circuit according to another embodiment.

FIG. 66C is a schematic diagram of an IC interface including an EOSprotection circuit according to another embodiment.

FIG. 67 is one example of a graph of voltage versus time for the EOSprotection circuit of FIG. 66A.

FIG. 68A is a schematic diagram of an IC interface including an EOSprotection circuit according to another embodiment.

FIG. 68B is a schematic diagram of an IC interface including an EOSprotection circuit according to another embodiment.

FIG. 69 is a schematic diagram of an example radio frequency module thatincludes a radio frequency component and an integrated antenna accordingto an embodiment.

FIG. 70 is a cross sectional view of the radio frequency module of FIG.1 prior to forming a shielding layer over the radio frequency componentaccording to an embodiment.

FIG. 71 is a cross sectional view of the radio frequency module of FIG.1 with a shielding layer over the radio frequency component and not overthe antenna according to an embodiment.

FIG. 72A is a flow diagram of an illustrative process that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment.

FIGS. 72B, 72C, 72D, and 72E illustrate an example module or strip ofmodules corresponding to various stages of the process of FIG. 72Aaccording to an embodiment.

FIG. 73A is a flow diagram of another illustrative process that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment.

FIGS. 73B, 73C, 73D, 73E, and 73F illustrate an example module or stripof modules corresponding to various stages of the process of FIG. 73Aaccording to an embodiment.

FIG. 74A is a flow diagram of another illustrative process that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment.

FIGS. 74B, 74C, 74D, 74E, and 74F illustrate an example module, strip ofmodules, or group of modules corresponding to various stages of theprocess of FIG. 74A according to an embodiment.

FIG. 75A is a flow diagram of another illustrative process that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment.

FIGS. 75B, 75C, 75D, 75E, and 75F illustrate an example module or groupof modules corresponding to various stages of the process of FIG. 7Aaccording to an embodiment.

FIG. 76A is a flow diagram of another illustrative process that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment.

FIGS. 76B, 76C, 76D, 76E, 76F, 76G, 76H, and 76I illustrate an examplemodule, strip of modules, or group of modules corresponding to variousstages of the process of FIG. 76A according to an embodiment.

FIG. 77A is a schematic diagram of an example of a radio frequencymodule according to an embodiment.

FIG. 77B is a schematic diagram of an example of a radio frequencymodule according to an embodiment. FIG. 77C is another view of the radiofrequency module of FIG. 77B after a shielding layer and a conformalstructure are formed.

FIG. 77D is a schematic diagram of an example of a selectively shieldedradio frequency module according to an embodiment.

FIG. 77E is a schematic diagram of an example of a selectively shieldedradio frequency module according to an embodiment.

FIG. 77F is a schematic diagram of an example of a selectively shieldedradio frequency module according to an embodiment.

FIG. 77G illustrates an example of a shielded radio frequency modulewith an ablation pattern leaving a portion of the radio frequency moduleunshielded according to an embodiment.

FIG. 77H illustrates an example of a selectively shielded radiofrequency module according to an embodiment.

FIG. 77I illustrates an example of a selectively shielded radiofrequency module with an unshielded portion between two shieldedportions according to an embodiment.

FIG. 77J illustrates an example of a selectively shielded radiofrequency module with an unshielded portion between shielded portionsaccording to an embodiment.

FIGS. 78A and 78B illustrate a radio frequency module that includes anintegrated antenna implemented on opposing sides of a package substrateaccording to an embodiment. FIG. 78A is a top view of the radiofrequency module. FIG. 78B is a bottom view of the radio frequencymodule.

FIG. 79A illustrates a radio frequency module that includes anintegrated antenna partially implemented over molding material accordingto an embodiment. FIG. 79B illustrates another view of the radiofrequency module of FIG. 79A.

FIG. 80 illustrates an RF module with an integrated antenna shieldedfrom an RF component according to an embodiment.

FIG. 81A illustrates an RF module with a through mold via according toan embodiment. FIG. 81B illustrates an RF module after the conductivelayer shown in FIG. 81A is removed over an antenna according to anembodiment.

FIG. 82A is a top view of a shielded RF component on a carrier with aprinted antenna according to an embodiment. FIG. 82B is a side view ofthe shielded RF component on the carrier with the printed antenna.

FIG. 83A shows a cross section of an antenna in a package systemaccording to an embodiment.

FIG. 83B shows a cross section of an antenna in a package systemaccording to an embodiment.

FIG. 84 shows a cross section of an antenna in a package system withsolder bumps providing standoff according to an embodiment.

FIG. 85A illustrates a system board assembly with an antenna in apackage module and another component disposed on a system boardaccording to an embodiment.

FIG. 85B illustrates cross section of a system board assembly with anantenna in a package module and another component disposed on a systemboard according to an embodiment.

FIG. 85C illustrates cross section of a system board assembly with anantenna in a package module and another component disposed on a systemboard according to an embodiment.

FIG. 86 is a cross sectional view of an antenna in a package systemaccording to an embodiment.

FIG. 87A is an example cross sectional view of layers radio frequencycircuit assembly with an integrated antenna according to an embodiment.

FIG. 87B is example cross sectional view of layers radio frequencycircuit assembly with an integrated antenna according to anotherembodiment.

FIG. 88A illustrates an example printed antenna of a radio frequencycircuit assembly according to an embodiment.

FIG. 88B illustrates an example printed antenna of a radio frequencycircuit assembly according to another embodiment.

FIG. 89A is an illustrate example of radio frequency component layer ofa radio frequency circuit assembly according to an embodiment.

FIG. 89B is an illustrate example of radio frequency component layer ofa radio frequency circuit assembly according to another embodiment.

FIG. 89C is an illustrate example of radio frequency component layer ofa radio frequency circuit assembly according to another embodiment.

FIG. 89D is an illustrate example of radio frequency component layer ofa radio frequency circuit assembly according to another embodiment.

FIG. 90A illustrates a top view of a multi-chip module. FIG. 90Billustrates a block diagram of the multi-chip module. FIG. 90Cillustrates a side view of the multi-chip module.

FIG. 91 illustrates an embodiment of a system-in-a-package for use in awireless device, according to certain embodiments.

FIG. 92 illustrates another embodiment of a system-in-a-package for usein a wireless device, according to certain embodiments.

FIG. 93 illustrates another embodiment of a system-in-a-package for usein a wireless device, according to certain embodiments.

FIG. 94A illustrates another embodiment of a system-in-a-package for usein a wireless device, according to certain embodiments.

FIG. 94B illustrates another embodiment of a surface mount crystal foruse in a system-in-a-package, according to certain embodiments.

FIG. 94C illustrates another embodiment of a surface mount crystal foruse in a system-in-a-package, according to certain embodiments.

FIG. 94D illustrates another embodiment of a surface mount crystal foruse in a system-in-a-package, according to certain embodiments.

FIG. 95 illustrates another embodiment of a system-in-a-package for usein a wireless device, according to certain embodiments.

FIG. 96 illustrates another embodiment of a system-in-a-package for usein a wireless device, according to certain embodiments.

FIG. 97 illustrates another embodiment of a system-in-a-package for usein a wireless device, according to certain embodiments.

FIG. 98A1 illustrates an example crystal assembly with conductivepillars, according to certain embodiments.

FIG. 98A2 illustrates an example crystal assembly with a conductivelayer in communication with the conductive pillars on one or more sides,according to certain embodiments.

FIG. 98B1 illustrates a cross sectional view of an example assemblyincluding a crystal and a front end integrated circuit, according tocertain embodiments.

FIG. 98B2 illustrates a cross sectional view of an example assemblyincluding a crystal and a surface acoustic wave (SAW) device, accordingto certain embodiments.

FIG. 98C illustrates a bottom view of an example crystal assembly,according the certain embodiments.

FIG. 98D illustrates an example system-in-a-package comprising a flipchip assembly above a crystal assembly, according to certainembodiments.

FIG. 98E illustrates an example system-in-a-package comprising a flipchip assembly beneath a crystal assembly, according to certainembodiments.

FIG. 98F illustrates an example circuit assembly comprising a FEICmounted to the lid of a crystal assembly, according to certainembodiments.

FIG. 99 illustrates an example stacked assembly including supports,according to certain embodiments.

FIGS. 100A-100D illustrate example bonding configurations for surfacemount devices, according to certain embodiments. FIG. 100A illustrateswires bond bonded between a bond source and a surface mount device. FIG.100B illustrates wire bond bonded between a bond source and ahorizontally oriented surface mount device. FIG. 100C illustrates wirebond bonded between a bond source and a vertically oriented surfacemount device. FIG. 100D illustrates a wire bond bonded between a bondsource and a vertically oriented surface mount device and another wirebond bonded between the surface mount device and a bondable device.

FIG. 101A1 illustrates a first example stacking configuration forsurface mount devices, according to certain embodiments.

FIG. 101A2 illustrates an example circuit diagram for the stackingconfiguration of FIG. 101A1, according to certain embodiments.

FIG. 101B1 illustrates a second example stacking configuration forsurface mount devices, according to certain embodiments.

FIG. 101B2 illustrates an example circuit diagram for the stackingconfiguration of FIG. 101B1, according to certain embodiments.

FIG. 101C1 illustrates a third example stacking configuration forsurface mount devices, according to certain embodiments.

FIG. 101C2 illustrates a fourth example stacking configuration forsurface mount devices, according to certain embodiments.

FIG. 101C3 illustrates an example circuit diagram for the stackingconfiguration of FIGS. 101C1 and 101C2, according to certainembodiments.

FIG. 101C1 illustrates a fifth example stacking configuration forsurface mount devices, according to certain embodiments.

FIG. 101C2 illustrates an example circuit diagram for the stackingconfiguration of FIG. 101C1, according to certain embodiments.

FIG. 101E illustrates an example circuit board layout, according tocertain embodiments.

FIG. 101F illustrates an example circuit board layout with examplebonding configurations and example stacking configurations, according tocertain embodiments.

FIG. 102 illustrates an embodiment of a stacked assembly, according tocertain embodiments.

FIG. 103 illustrates another embodiment of a stacked assembly, accordingto certain embodiments.

FIG. 104 illustrates an example stacked assembly including supports andspacers, according to certain embodiments.

FIG. 105 illustrates an example circuit assembly including a pluralityof stacked assemblies, according to certain embodiments.

FIG. 106 is an example block diagram of a system-in-a package for use ina wireless device, according to certain embodiments.

FIG. 107 is an example block diagram illustrating a simplified wirelessdevice including a system-in-a-package, according to certainembodiments.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following description of certain embodiments presents variousdescriptions of specific embodiments. However, the innovations describedherein can be embodied in a multitude of different ways, for example, asdefined and covered by the claims. In this description, reference ismade to the drawings where like reference numerals can indicateidentical or functionally similar elements. It will be understood thatelements illustrated in the figures are not necessarily drawn to scale.Moreover, it will be understood that certain embodiments can includemore elements than illustrated in a drawing and/or a subset of theelements illustrated in a drawing. Further, some embodiments canincorporate any suitable combination of features from two or moredrawings. The headings provided herein are for convenience only and donot necessarily affect the scope or meaning of the claims.

Front End Systems

A front end system can be used to handle signals being transmittedand/or received via one or more antennas. For example, a front endsystem can include switches, filters, amplifiers, and/or other circuitryin signal paths between one or more antennas and a transceiver.

Implementing one or more features described herein in a front end systemcan achieve a number of advantages, including, but not limited to, oneor more of higher power added efficiency (PAE), more compact layout,lower cost, higher linearity, superior robustness to overstress, and/orenhanced integration. Moreover, implementing one or more featuresdescribed herein in a front end system can achieve desirable figure ofmerit (FOM) and/or other metrics by which front end systems are rated.Although some features are described herein in connection with front endsystems for illustrative purposes, it will be understood that theprinciples and advantages described herein can be applied to a widevariety of other electronics.

FIG. 1A illustrates a schematic block diagram of one example of a frontend system 10. The front end system 10 includes an antenna-side switch2, a transceiver-side switch 3, a bypass circuit 4, a power amplifier 5,a low noise amplifier (LNA) 6, and a control and biasing circuit 7. Thefront end system 10 can incorporate one or more features described inthe sections herein.

Although one example of a front end system is shown in FIG. 1A, a frontend system can be adapted in a wide variety of ways. For example, afront end system can include more or fewer components and/or signalspaths. Accordingly, the teachings herein are applicable to front endsystems implemented in a wide variety of ways.

In certain implementations, a front end system, such as the front endsystem 10 of FIG. 1A, is implemented on an integrated circuit orsemiconductor die. In such implementations, the front end system can bereferred to as a front end integrated circuit (FEIC). In otherimplementations, a front end system is implemented as a module. In suchimplementations, the front end system can be referred to as a front endmodule (FEM).

Accordingly, in some implementations, the front end system 10 isimplemented in a packaged module. Such packaged modules can include arelatively low cost laminate and one or more dies that combine low noiseamplifiers with power amplifiers and/or switch functions. Some suchpackaged modules can be multi-chip modules. In certain implementations,some or the all of the illustrated components of the front end system 10can be embodied on a single integrated circuit or die. Such a die can bemanufactured using any suitable process technology. As one example, thedie can be a semiconductor-on-insulator die, such as asilicon-on-insulator (SOI) die.

As shown in FIG. 1A, the front end system 10 includes multiple signalpaths between the antenna-side switch 2 and the transceiver-side switch3. For example, the illustrated front end system 10 includes a bypasssignal path that includes the bypass circuit 4, a transmit signal paththat includes the power amplifier 5, and a receive signal path thatincludes the LNA 6. Although an example with three signal paths isshown, a front end system can include more or fewer signal paths.

The antenna-side switch 2 is used to control connection of the signalpaths to an antenna (not shown in FIG. 1A). For example, theantenna-side switch 2 can be used to connect a particular one of thetransmit signal path, the receive signal path, or the bypass signal pathto an antenna. Additionally, the transceiver-side switch 3 is used tocontrol connection of the signal paths to a transceiver (not shown inFIG. 1A). For example, the transceiver-side switch 3 can be used toconnect a particular one of the transmit signal path, the receive signalpath, or the bypass signal path to a transceiver. In certainimplementations, the antenna-side switch 2 and/or the transceiver-sideswitch 3 are implemented as multi-throw switches.

FIG. 1B illustrates a schematic block diagram of another example of afront end system 20. The front end system 20 of FIG. 1B is similar tothe front end system 10 of FIG. 1A, except that the front end system 20further includes an integrated antenna 11. In certain implementations, afront end system includes an integrated antenna. For example, a frontend system can be implemented on a module along with one or moreintegrated antennas.

With reference to FIGS. 1A and 1B, the bypass network 4 can include anysuitable network for matching and/or bypassing the receive signal pathand the transmit signal path. The bypass network 4 can be implemented,for instance, by a passive impedance network or by a conductive trace orwire.

The LNA 6 can be used to amplify a received signal from the antenna. TheLNA 6 can be implemented in a wide variety of ways.

In certain embodiments, the LNA 6 is implemented in accordance with oneor more features of Section I (Low Noise Amplifier with ImpedanceTransformation Circuit). For example, the LNA 6 can be implemented withmagnetic coupling between a degeneration inductor (e.g., a sourcedegeneration inductor or an emitter degeneration inductor) and a seriesinput inductor. These magnetically coupled inductors can in effectprovide a transformer, with a primary winding in series with the inputand a secondary winding electrically connected where the degenerationinductor is electrically connected to the amplifying device (e.g., atthe source of a field effect transistor amplifying device or at theemitter of a bipolar transistor amplifying device). Providingmagnetically coupled inductors in this manner allows the input matchinductor to have a relatively low inductance value and correspondingsmall size. Moreover, negative feedback provided by the magneticallycoupled inductors can provide increased linearity to the LNA 6.

In certain embodiments, the LNA 6 and the antenna-side switch 2 areimplemented in accordance with one or more features of Section II(Overload Protection of Low Noise Amplifier). For example, theantenna-side switch 2 can include an analog control input forcontrolling an impedance between an antenna and an input to the LNA 6.Additionally, an overload protection circuit is included to providefeedback to the switch's analog control input based on detecting asignal level of the LNA 6. Thus, the overload protection circuit detectswhether or not the LNA 6 is overloaded. Additionally, when the overloadprotection circuit detects an overload condition, the overloadprotection circuit provides feedback to the analog control input of theswitch to increase the impedance of the switch and reduce the magnitudeof the input signal received by the LNA 6. Implementing the LNA 6 andthe antenna-side switch 2 in this manner limits large current and/orvoltage swing conditions manifesting within amplification transistors ofthe LNA 6.

The power amplifier 5 can be used to amplify a transmit signal receivedfrom a transceiver for transmission via an antenna. The power amplifier5 can be implemented in a wide variety of ways.

In certain implementations, the power amplifier 5 is implemented inaccordance with one or more features of Section III (Multi-Mode PowerAmplifier). For example, the power amplifier 5 can include a stackedoutput stage and a bias circuit that biases the stacked transistors ofthe stacked output stage based on mode. In one example, the bias circuitcan bias a transistor in a stack to a linear region of operation in afirst mode, and bias the transistor as a switch in a second mode.Accordingly, the bias circuit can bias the stacked output stage suchthat the stacked output stage behaves like there are fewer transistorsin the stack in the second mode relative to the first mode. Suchoperation can result in meeting design specifications for differentpower modes, in which a supply voltage provided to the stacked outputstage changes based on mode.

In certain implementations, the power amplifier 5 is implemented inaccordance with one or more features of Section IV (Power Amplifier withInjection-Locked Oscillator Driver Stage). For example the poweramplifier 5 can include a driver stage implemented using aninjection-locked oscillator and an output stage having an adjustablesupply voltage that changes with a mode of the power amplifier 5. Byimplementing the power amplifier 5 in this manner, the power amplifier 5exhibits excellent efficiency, including in a low power mode. Forexample, in the low power mode, the adjustable supply voltage used topower the output stage is decreased, and the driver stage has arelatively large impact on overall efficiency of the power amplifier 5.By implementing the power amplifier 5 in this manner, the poweramplifier's efficiency can be enhanced, particularly in applications inwhich the power amplifier's output stage operates with large differencesin supply voltage in different modes of operation.

With continuing reference to FIGS. 1A and 1B, the control and biasingcircuit 7 can be used to control and bias various front end circuitry.For example, the control and biasing circuit 7 can receive controlsignal(s) for controlling the LNA 6, the antenna-side switch 2, thetransceiver-side switch 3, and/or the power amplifier 5. The controlsignals can be provided to the control and biasing circuit 7 in avariety of ways, such as over an input pad of a die. In one example, thecontrol signals include at least one of a mode signal or a bias controlsignal.

The front end system 10 of FIG. 1A and the front end system 20 of FIG.1B can be implemented on one or more semiconductor dies. In certainimplementations, at least one of the semiconductor dies includes pins orpads protected using an electrical overstress (EOS) protection circuitimplemented in accordance with one or more features of Section V(Electrical Overstress Protection). For example, an EOS protectioncircuit can include an overstress sensing circuit electrically connectedbetween a pad of a semiconductor die and a first supply node, animpedance element electrically connected between the pad and a signalnode, a controllable clamp electrically connected between the signalnode and the first supply node and selectively activatable by theoverstress sensing circuit, and an overshoot limiting circuitelectrically connected between the signal node and a second supply node.The overstress sensing circuit activates the controllable clamp when anEOS event is detected at the pad. Thus, the EOS protection circuit isarranged to divert charge associated with the EOS event away from thesignal node to provide EOS protection. By implementing a front endsystem in this manner can achieve enhanced EOS protection, lower staticpower dissipation, and/or a more compact chip layout. In certainimplementations, the pad is an input pad that receives a control signalfor controlling the power amplifier 5 and/or LNA 6.

In accordance with certain embodiments, the front end systems of FIGS.1A and/or 1B can include RF shielding and/or RF isolation structures. Incertain implementations, the front end systems of FIGS. 1A and/or 1B areimplemented in accordance with one or more features of Section VI(Selective Shielding of Radio Frequency Modules). For example, the frontend system can be implemented as a radio frequency module that ispartially shielded. Additionally, a shielding layer is included over ashielded portion of the radio frequency module and an unshielded portionof the radio frequency module is unshielded. The shielding layer canshield certain components of the front end system (for instance, thepower amplifier 5 and/or LNA 6) and leave other components (forinstance, the integrated antenna 11) unshielded.

In certain implementations, the front end systems of FIGS. 1A and/or 1Bare implemented in accordance with one or more features of Section VII(Shielded Radio Frequency Component with Integrated Antenna). Forexample, the front end system can include a laminated substrateincluding an antenna is printed on a top layer and a ground plane forshielding on a layer underneath the top layer. Additionally, at leastone electronic component of the front end can be disposed along a bottomlayer of the laminate substrate, and solder bumps are disposed aroundthe electronic component and electrically connected to the ground plane.The solder bumps can attach the module to a carrier or directly to asystem board. The electronic component can be surrounded by solderbumps, and the outside edges of the electronic component can have groundsolder bumps that are connected to the ground plane by way of vias.Accordingly, a shielding structure with can be completed when the moduleis placed onto a carrier or system board, and the shielding structurecan serve as a Faraday cage around the electronic component.

In certain embodiments, the front end systems disclosed herein areimplemented on a semiconductor die as front end integrated circuit(FEIC). In certain implementations, a FEIC is implemented in accordancewith one or more features of Section VIII (Packaged Module with StackedComponents). For example, the FEIC can be included in a packaged modulethat stacks multiple chips and passive components, such as capacitorsand resistors, into a compact area on a package substrate. Byimplementing an FEIC in such a packaged module, a smaller footprintand/or a more compact substrate area can be achieved.

In accordance with certain embodiments, a packaged module includes aFEIC, a crystal oscillator and a system on a chip (SoC), such as atransceiver die. In certain implementations, the packaged module isimplemented in accordance with one or more features of Section VIII. Forexample, the SoC can be stacked over a crystal assembly to save spaceand provide shorter crystal traces. The crystal assembly includes thecrystal oscillator housed in a housing that includes one or moreconductive pillars for routing signals from the SoC to a substrateand/or to provide thermal conductivity.

In accordance with certain embodiments, a packaged module includes aFEIC, a filter assembly and a SoC. In certain implementations, thepackaged module is implemented in accordance with one or more featuresof Section VIII. For example, the filter assembly can be stacked withother dies and components of the packaged module to reduce a footprintof the packaged module. Furthermore, stacking the filter assembly inthis manner can reduce lengths of signal carrying conductors, therebyreducing parasitics and enhancing signaling performance.

Front end systems discussed herein can include a power amplifier and alow noise amplifier. Such a front end system can operate with improvedperformance and/or efficiency. The front end system can be a front endmodule and/or a front end integrated circuit. In certain embodiments,the power amplifier and the low noise amplifier can be embodied on acommon semiconductor-on-insulator die, such as a commonsilicon-on-insulator die. The power amplifier and the low noiseamplifier can both be coupled to a common switch. The common switch canbe an antenna-side switch, for example. The power amplifier can beimplemented in accordance with any suitable principles and advantagesdiscussed herein. The low noise amplifier can be implemented inaccordance with any suitable principles and advantages discussed herein.Some example front end systems that include a power amplifier and a lownoise amplifier will be described with reference to FIGS. 2 to 5.

FIG. 2 is a schematic block diagram of a front end system 30 thatincludes a multi-mode power amplifier 31 and a low noise amplifier 32with magnetically coupled inductors according to an embodiment. Themulti-mode power amplifier 31 is in a transmit path of the front endsystem 30. The multi-mode power amplifier 31 is an example of the poweramplifier 5 discussed above. The multi-mode power amplifier 31 includesa stacked output stage including a transistor stack of two or moretransistors. The multi-mode power amplifier 31 also includes a biascircuit configured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifier. Themulti-mode power amplifier 31 can include any suitable combination offeatures discussed in Section III. The low noise amplifier 32 is in areceive path of the front end system 30. The low noise amplifier 32 isan example of the low noise amplifier 6 discussed above. The low noiseamplifier 32 includes a first inductor, an amplification circuit, and asecond inductor magnetically coupled to the first inductor to providenegative feedback to linearize the low noise amplifier. The low noiseamplifier 32 can include any suitable combination of features discussedin Section I. The front end system 30 also includes a radio frequencyswitch 33. The radio frequency switch 33 is an example of theantenna-side switch 2 discussed above. The radio frequency switch 33 canbe any suitable multi-throw switch configured to pass radio frequencysignals. The radio frequency switch 33 can electrically couple a commonnode to the transmit path in a first state and to electrically couplethe common node to the receive path in a second state. The common nodecan be an antenna port of the radio frequency switch 33.

FIG. 3 is a schematic block diagram of a front end system 34 thatincludes a power amplifier 35 an injection-locked oscillator driverstage and a low noise amplifier 32 with magnetically coupled inductorsaccording to an embodiment. The power amplifier 35 is in a transmit pathof the front end system 34. The power amplifier 35 is an example of thepower amplifier 5 discussed above. The power amplifier 35 includes aninjection-locked oscillator driver stage. The power amplifier 35 caninclude any suitable combination of features discussed in Section IV.The low noise amplifier 32 is in a receive path of the front end system34. The low noise amplifier 32 is an example of the low noise amplifier6 discussed above. The low noise amplifier 32 includes a first inductor,an amplification circuit, and a second inductor magnetically coupled tothe first inductor to provide negative feedback to linearize the lownoise amplifier. The low noise amplifier 32 can include any suitablecombination of features discussed in Section I. The front end system 34also includes a radio frequency switch 33. The radio frequency switch 33is an example of the antenna-side switch 2 discussed above. The radiofrequency switch 33 can be any suitable multi-throw switch configured topass radio frequency signals. The radio frequency switch 33 canelectrically couple a common node to the transmit path in a first stateand to electrically couple the common node to the receive path in asecond state. The common node can be an antenna port of the radiofrequency switch 33.

FIG. 4 is a schematic block diagram of a front end system 36 thatincludes a radio frequency switch 33, a power amplifier 35, a low noiseamplifier 37, and an overload protection circuit 38 according to anembodiment. The radio frequency switch 33 is an example of theantenna-side switch 2 discussed above. The low noise amplifier 37 is anexample of the low noise amplifier 6 discussed above. The low noiseamplifier 37 includes an input electrically coupled to a first throw ofthe radio frequency switch 33. The overload protection circuit 38 isconfigured to adjust an impedance of the radio frequency switch 33 basedon a signal level of the low noise amplifier 37. The low noise amplifier37 and/or the overload protection circuit 38 can include any suitablecombination of features discussed in Section II. The power amplifier 35is an example of the power amplifier 5 discussed above. The poweramplifier 35 includes an output electrically coupled to a second throwof the radio frequency switch 33. The power amplifier 35 includes aninjection-locked oscillator driver stage. The power amplifier 35 caninclude any suitable combination of features discussed in Section IV.

FIG. 5 is a schematic block diagram of a front end system 39 thatincludes a radio frequency switch 33, a low noise amplifier 37, anoverload protection circuit 38, and a multi-mode power amplifier 31according to an embodiment. The radio frequency switch 33 is an exampleof the antenna-side switch 2 discussed above. The low noise amplifier 37is an example of the low noise amplifier 6 discussed above. The lownoise amplifier 37 includes an input electrically coupled to a firstthrow of the radio frequency switch 33. The overload protection circuit38 is configured to adjust an impedance of the radio frequency switch 33based on a signal level of the low noise amplifier 37. The low noiseamplifier 37 and/or the overload protection circuit 38 can include anysuitable combination of features discussed in Section II. The multi-modepower amplifier 31 is an example of the power amplifier 5 discussedabove. The multi-mode power amplifier 31 includes a stacked output stageincluding a transistor stack of two or more transistors. The multi-modepower amplifier 31 also includes a bias circuit configured to control abias of at least one transistor of the transistor stack based on a modeof the multi-mode power amplifier. The multi-mode power amplifier 31 caninclude any suitable combination of features discussed in Section III.

Front end integrated circuits can include overstress protection. Anoverstress protection circuit can provide electrical overstressprotection to an input/output pad of the front end integrated circuit.Such a front end integrated circuit can include a power amplifierimplemented in accordance with any suitable principles and advantagesdiscussed herein and/or a low noise amplifier implemented in accordancewith any suitable principles and advantages discussed herein. Someexample front end integrated circuits that include overstress protectioncircuits will be described with reference to FIGS. 6 to 9.

FIG. 6 is a schematic block diagram of a front end integrated circuit 40that includes an overstress protection circuit and a low noise amplifier32 with magnetically coupled inductors according to an embodiment. Thelow noise amplifier 32 is an example of the low noise amplifier 6discussed above. The low noise amplifier 32 includes a first inductor,an amplification circuit, and a second inductor magnetically coupled tothe first inductor to provide negative feedback to linearize the lownoise amplifier. The low noise amplifier 32 is controllable by a controlsignal. The low noise amplifier 32 can include any suitable combinationof features discussed in Section I. The front end integrated circuit 40also includes an input pad 41 configured to receive the control signal.The overstress protection circuit includes an overstress sensing circuit42 electrically connected between the input pad 41 and a first supplynode V₁, an impedance element 43 electrically connected between theinput pad 41 and a signal node, and a controllable clamp 44 electricallyconnected between the signal node and the first supply node V₁. Theoverstress sensing circuit 42 is configured to activate the controllableclamp 44 in response to detecting an electrical overstress event at theinput pad 41. An electrostatic discharge (ESD) event is an example of anelectrical overstress event. The input pad 41 and/or the overstressprotection circuit can include any suitable combination of featuresdiscussed in Section V.

FIG. 7 is a schematic block diagram of a front end integrated circuit 46that includes an overstress protection circuit and a low noise amplifiersystem according to an embodiment. The low noise amplifier systemincludes an antenna-side switch 47, a low noise amplifier 37 includingan input electrically coupled to the antenna-side switch 47, and anoverload protection circuit 38 configured to adjust an impedance of theantenna-side switch 47 based on a signal level of the low noiseamplifier 37. The low noise amplifier 37 is controllable by a controlsignal. The low noise amplifier 37 is an example of the low noiseamplifier 6 discussed above. The antenna-side switch 47 is an example ofthe antenna-side switch 2 discussed above. The low noise amplifier 37,the overload protection circuit 38, and/or the antenna-side switch 47can include any suitable combination of features discussed in SectionII. The front end integrated circuit 46 also includes an input pad 41configured to receive the control signal. The overstress protectioncircuit includes an overstress sensing circuit 42 electrically connectedbetween the input pad 41 and a first supply node V₁, an impedanceelement 43 electrically connected between the input pad 41 and a signalnode, and a controllable clamp 44 electrically connected between thesignal node and the first supply node V₁. The overstress sensing circuit42 is configured to activate the controllable clamp 44 in response todetecting an electrical overstress event at the input pad 41. Anelectrostatic discharge (ESD) event is an example of an electricaloverstress event. The input pad 41 and/or the overstress protectioncircuit can include any suitable combination of features discussed inSection V.

FIG. 8 is a schematic block diagram of a front end integrated circuit 48that includes an overstress protection circuit and a multi-mode poweramplifier 31 according to an embodiment. The multi-mode power amplifier31 is an example of the power amplifier 5 discussed above. Themulti-mode power amplifier 31 includes a stacked output stage includinga transistor stack of two or more transistors. The multi-mode poweramplifier 31 also includes a bias circuit configured to control a biasof at least one transistor of the transistor stack based on a mode ofthe multi-mode power amplifier 31. The multi-mode power amplifier 31 iscontrollable by a control signal. The multi-mode power amplifier 31 caninclude any suitable combination of features discussed in Section III.The front end integrated circuit 48 also includes an input pad 41configured to receive the control signal. The overstress protectioncircuit includes an overstress sensing circuit 42 electrically connectedbetween the input pad 41 and a first supply node V₁, an impedanceelement 43 electrically connected between the input pad 41 and a signalnode, and a controllable clamp 44 electrically connected between thesignal node and the first supply node V₁. The overstress sensing circuit42 is configured to activate the controllable clamp 44 in response todetecting an electrical overstress event at the input pad 41. Anelectrostatic discharge (ESD) event is an example of an electricaloverstress event. The input pad 41 and/or the overstress protectioncircuit can include any suitable combination of features discussed inSection V.

FIG. 9 is a schematic block diagram of a front end integrated circuit 49that includes an overstress protection circuit and a power amplifier 35that includes an injection-locked oscillator driver stage according toan embodiment. The power amplifier 35 is an example of the poweramplifier 5 discussed above. The power amplifier 35 includes aninjection-locked oscillator driver stage. The power amplifier 35 iscontrollable by a control signal. The power amplifier 35 can include anysuitable combination of features discussed in Section IV. The front endintegrated circuit 49 also includes an input pad 41 configured toreceive the control signal. The overstress protection circuit includesan overstress sensing circuit 42 electrically connected between theinput pad 41 and a first supply node V₁, an impedance element 43electrically connected between the input pad 41 and a signal node, and acontrollable clamp 44 electrically connected between the signal node andthe first supply node V₁. The overstress sensing circuit 42 isconfigured to activate the controllable clamp 44 in response todetecting an electrical overstress event at the input pad 41. Anelectrostatic discharge (ESD) event is an example of an electricaloverstress event. The input pad 41 and/or the overstress protectioncircuit can include any suitable combination of features discussed inSection V.

Packaged modules can include an integrated antenna and a frontintegrated circuit on a common packaging substrate. The front endintegrated circuit can be positioned in an interior of a radio frequencyshielding structure. The shielding structure can include a shieldinglayer formed over a front end integrated such that the antenna isunshielded opposite the common packaging substrate. The radio frequencyshielding structure can shield the front end integrated circuit fromelectromagnetic interference from the integrated antenna and/or fromother components outside of the radio frequency shielding structure.Alternatively or additionally, the radio frequency shielding structurecan shield the antenna and/or other components from electromagneticinterference from the front end integrated circuit. Accordingly, anantenna can be integrated in a packaged module and the radio frequencyshielding structure can reduce electromagnetic interference betweencomponents of a packaged module. According to some embodiments, theintegrated antenna can be a multi-layer antenna. In some instances,multi-layer antenna can have a first portion implemented on a first sideof the substrate and a second portion in implemented on a second side ofthe substrate that is opposite to the first side of the substrate. Someexample packaged modules with an integrated antenna and a front endintegrated circuit on an interior of a radio frequency shieldingstructure will be described with reference to FIGS. 10 to 14. FIGS. 10to 14 illustrate packaged modules without a shielding layer that isformed over the front end integrated circuit and not over the antenna.Such a shielding layer can be formed, for example, in accordance withany of the principles and advantages discussed in Section VI.

FIG. 10 is a schematic diagram of a packaged module 50 that includes alow noise amplifier 32 with magnetically coupled inductors within aradio frequency shielding structure 51 and an antenna 52 external to theradio frequency shielding structure 51 according to an embodiment. FIG.10 shows the packaged module 50 in plan view without a top shieldinglayer of the radio frequency shielding structure 51. The packaged module50 includes a package substrate 53, a radio frequency shieldingstructure 51 extending above the package substrate 53, and a front endintegrated circuit 54 positioned in an interior of the radio frequencyshielding structure 51, and an antenna 52 on the package substrate 53external to the radio frequency shielding structure 51. The radiofrequency shielding structure 51 can include one or more suitablefeatures discussed in Section VI. The antenna 52 can include one or moresuitable features discussed in Section VI. The package substrate 53 caninclude one or more suitable features discussed in Section VI. The frontend integrated circuit 54 includes a low noise amplifier 32 thatincludes a first inductor, an amplification circuit, and a secondinductor magnetically coupled to the first inductor to provide negativefeedback to linearize the low noise amplifier 32. The low noiseamplifier 32 is an example of the low noise amplifier 6 discussed above.The low noise amplifier 32 can include any suitable combination offeatures discussed in Section I.

FIG. 11 is a schematic diagram of a packaged module 55 that includes alow noise amplifier 37 and an overprotection circuit 38 within a radiofrequency shielding structure 52 and an antenna external to the radiofrequency shielding structure 52 according to an embodiment. FIG. 11shows the packaged module 55 in plan view without a top shielding layerof the radio frequency shielding structure 51. The packaged module 55includes a package substrate 53, a radio frequency shielding structure51 extending above the package substrate 53, and a front end integratedcircuit 54′ positioned in an interior of the radio frequency shieldingstructure 51, and an antenna 52 on the package substrate 53 external tothe radio frequency shielding structure 51. The radio frequencyshielding structure 51 can include one or more suitable featuresdiscussed in Section VI. The antenna 52 can include one or more suitablefeatures discussed in Section VI. The package substrate 53 can includeone or more suitable features discussed in Section VI. The front endintegrated circuit 54′ includes an antenna-side switch 47, a low noiseamplifier 37 including an input electrically coupled to the antenna-sideswitch 47, and an overload protection circuit 38 configured to adjust animpedance of the antenna-side switch 47 based on a signal level of thelow noise amplifier 37. The low noise amplifier 37 is an example of thelow noise amplifier 6 discussed above. The antenna-side switch 47 is anexample of the antenna-side switch 2 discussed above. The low noiseamplifier 37 and/or the overload protection circuit 38 and/or theantenna-side switch 47 can include any suitable combination of featuresdiscussed in Section II.

FIG. 12 is a schematic diagram of a packaged module 56 that includes amulti-mode power amplifier 31 within a radio frequency shieldingstructure 51 and an antenna 52 external to the radio frequency shieldingstructure 51 according to an embodiment. The packaged module 56 includesa package substrate 53, a radio frequency shielding structure 51extending above the package substrate 53, and a front end integratedcircuit 54″ positioned in an interior of the radio frequency shieldingstructure 51, and an antenna 52 on the package substrate 53 external tothe radio frequency shielding structure 51. The radio frequencyshielding structure 51 can include one or more suitable featuresdiscussed in Section VI. The antenna 52 can include one or more suitablefeatures discussed in Section VI. The package substrate 53 can includeone or more suitable features discussed in Section VI. The front endintegrated circuit 54″ includes a multi-mode power amplifier 31 thatincludes a stacked output stage including a transistor stack of two ormore transistors. The multi-mode power amplifier 31 also includes a biascircuit configured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifier. Themulti-mode power amplifier 31 is an example of the power amplifier 5discussed above. The multi-mode power amplifier 31 can include anysuitable combination of features discussed in Section III.

FIG. 13 is a schematic diagram of a packaged module 57 that includes apower amplifier 35 with an injection-locked oscillator driver stagewithin a radio frequency shielding structure 51 and an antenna 52external to the radio frequency shielding structure 51 according to anembodiment. The packaged module 56 includes a package substrate 53, aradio frequency shielding structure 51 extending above the packagesubstrate 53, and a front end integrated circuit 54′″ positioned in aninterior of the radio frequency shielding structure 51, and an antenna52 on the package substrate 53 external to the radio frequency shieldingstructure 51. The radio frequency shielding structure 51 can include oneor more suitable features discussed in Section VI. The antenna 52 caninclude one or more suitable features discussed in Section VI. Thepackage substrate 53 can include one or more suitable features discussedin Section VI. The front end integrated circuit 54′″ includes aninjection-locked oscillator driver stage. As illustrated, the poweramplifier 35 includes an injection-locked oscillator driver stage. Thepower amplifier 35 is an example of the power amplifier 5 discussedabove. The power amplifier 35 and/or the injection-locked oscillatordriver stage can include any suitable combination of features discussedin Section IV.

FIG. 14 is a schematic diagram of a packaged module 58 that includes anoverstress protection circuit within a radio frequency shieldingstructure 51 and an antenna 52 external to the radio frequency shieldingstructure 51 according to an embodiment. The packaged module 56 includesa package substrate 53, a radio frequency shielding structure 51extending above the package substrate 53, and a front end integratedcircuit 54′″ positioned in an interior of the radio frequency shieldingstructure 51, and an antenna 52 on the package substrate 53 external tothe radio frequency shielding structure 51. The radio frequencyshielding structure 51 can include one or more suitable featuresdiscussed in Section VI. The antenna 52 can include one or more suitablefeatures discussed in Section VI. The package substrate 53 can includeone or more suitable features discussed in Section VI. The front endintegrated circuit 54′″ includes a pad 41, an overstress protectioncircuit, and an internal circuit 59 electrically connected to a signalnode. The overstress protection circuit includes an overstress sensingcircuit 42 electrically connected between the pad 41 and a first supplynode V₁, an impedance element 43 electrically connected between the pad41 and the signal node, and a controllable clamp 44 electricallyconnected between the signal node and the first supply node V₁. Theoverstress sensing circuit 42 is configured to activate the controllableclamp 44 in response to detecting an electrical overstress event at thepad 41. The overstress protection circuit can include any suitablecombination of features discussed in Section V.

Packaged modules can include an antenna shielded from a front integratedcircuit by a ground plane of a multi-layer substrate. The ground planecan shield the front end integrated circuit from electromagneticinterference from the antenna. Alternatively or additionally, the groundplane can shield the antenna from electromagnetic interference from thefront end integrated circuit. Accordingly, an antenna can be integratedin a packaged module and the ground plane can reduce electromagneticinterference between components of a packaged module. Some examplepackaged modules with a ground plane positioned between an antenna and afront end integrated circuit will be described with reference to FIGS.15A to 15F.

FIG. 15A is a cross section of a packaged module 60 that includes aground plane 61 between an antenna 62 and a front end integrated circuit63 according to an embodiment. The packaged module 60 includes amulti-layer substrate 64 including a ground plane 61, an antenna 62 on afirst side of the multi-layer substrate 64, and a front end integratedcircuit 63 on a second side of the multi-layer substrate 64. The groundplane 61 is positioned between the antenna 62 and the front endintegrated circuit 63. The ground plane 61 is operable to provideshielding for the front end integrated circuit 63. The packaged module60 can include any suitable combination of features discussed in SectionVII.

As illustrated, the packaged module 60 also includes an insulating layer65 disposed between the antenna layer 62 and the ground plane 61, otherlayers 66 (e.g., including signal routing and/or passive components),vias 67 extending from the ground plane 61 to the bottom side of themulti-layer substrate 64, molding material 68 encapsulating the frontend integrated circuit 63, through mold vias 69 extending through themolding material 68, and solder bumps 70.

FIGS. 15B to 15F are example cross sections of the packaged module 60that include various front end integrated circuits 63. In these figures,ground solder bumps 70 surround a front end integrated circuit and forma portion of a shielding structure around the front end integratedcircuit. As illustrated, the ground solder bumps 70 surround signalrouting solder bumps 73. The signal routing solder bumps 73 provide atleast a portion of a connection between a front end integrated circuit63 with metal routing in a routing layer that is disposed between thefront end integrated circuit 63 and the ground plane 61. Although FIGS.15B to 15F illustrate circuitry included in a front end integratedcircuit, most front end integrated circuits will also include othercircuitry that is not illustrated in these figures. In some embodiments,a front end integrated circuit 63 includes circuitry associated with twoor more of FIGS. 15B to 15F.

As shown in FIG. 15B, the front end integrated circuit 63 can include alow noise amplifier 32 that includes a first inductor, an amplificationcircuit, and a second inductor magnetically coupled to the firstinductor to provide negative feedback to linearize the low noiseamplifier 32. The low noise amplifier 32 is an example of the low noiseamplifier 6 discussed above. The low noise amplifier 32 can include anysuitable combination of features discussed in Section I.

As shown in FIG. 15C, the front end integrated circuit 63 can include anantenna-side switch 47, a low noise amplifier 37 including an inputelectrically coupled to the antenna 62 via the antenna-side switch 47,and an overload protection circuit 38 configured to adjust an impedanceof the antenna-side switch 47 based on a signal level of the low noiseamplifier 37. The low noise amplifier 37 is an example of the low noiseamplifier 6 discussed above. The low noise amplifier 37 and/or theoverload protection circuit 38 can include any suitable combination offeatures discussed in Section II.

As shown in FIG. 15D, the front end integrated circuit 63 can include amulti-mode power amplifier 31 that includes a stacked output stageincluding a transistor stack of two or more transistors. The multi-modepower amplifier 31 also includes a bias circuit configured to control abias of at least one transistor of the transistor stack based on a modeof the multi-mode power amplifier. The multi-mode power amplifier 31 isan example of the power amplifier 5 discussed above. The multi-modepower amplifier 31 can include any suitable combination of featuresdiscussed in Section III.

As shown in FIG. 15E, the front end integrated circuit 63 can include aninjection-locked oscillator driver stage. As illustrated, a poweramplifier 35 includes an injection-locked oscillator driver stage. Thepower amplifier 35 is an example of the power amplifier 5 discussedabove. The power amplifier 35 and/or the injection-locked oscillatordriver stage can include any suitable combination of features discussedin Section IV.

As shown in FIG. 15F, the front end integrated circuit 63 can include apad (connected to a signal routing solder bump 73 in FIG. 15F), anoverstress protection circuit, and an internal circuit 59 electricallyconnected to a signal node. The overstress protection circuit includesan overstress sensing circuit 42 electrically connected between the padand a first supply node V₁, an impedance element 43 electricallyconnected between the pad and the signal node, and a controllable clamp44 electrically connected between the signal node and the first supplynode V₁. The overstress sensing circuit 42 is configured to activate thecontrollable clamp 44 in response to detecting an electrical overstressevent at the pad. The overstress protection circuit can include anysuitable combination of features discussed in Section V.

Packaged modules can include a crystal and integrated circuits within acommon package. Such packaged modules can include a crystal, a firstintegrated circuit (e.g., a system on a chip (SoC)) disposed between thecrystal and a substrate, and a second integrated circuit. Such apackaged module can be referred to as a system-in-a package (SiP). Someexample packaged modules with a first integrated circuit disposedbetween a crystal and a package substrate will be described withreference to FIGS. 16 to 20. These example modules include componentsarranged to achieve a relatively small module size. Such modules canhave decreased crystal trace parasitic capacitance and/or reducedcoupling between crystal routing traces and other relatively sensitivepaths within the module.

FIG. 16 is a cross section of a packaged module 80 that includes anintegrated circuit 81, a crystal 82 vertically integrated with theintegrated circuit 81, and an other integrated circuit 83 that includesa low noise amplifier 32 with magnetically coupled inductors accordingto an embodiment. The packaged module 80 includes a package substrate84, a first integrated circuit 81 supported by the package substrate 84,and a crystal 82 supported by the package substrate 84. The firstintegrated circuit 81 is disposed between the crystal 82 and the packagesubstrate 84. The packaged module 80 also includes a second integratedcircuit 83 supported by the package substrate 84. The second integratedcircuit 83 is not necessarily drawn to scale. As illustrated in FIG. 16,the packaged module 80 can also include a routing substrate orinterposer 85, one or more load capacitors 86, and one or more wirebonds 87. The package substrate 84 can include one or more suitablefeatures discussed in Section VIII. The first integrated circuit 81 caninclude one or more suitable features discussed in Section VIII. Thecrystal 82 can include one or more suitable features discussed inSection VIII. The second integrated circuit 83 can include any suitablefront end circuitry discussed herein. As illustrated, the secondintegrated circuit 83 includes a low noise amplifier 32 that includes afirst inductor, an amplification circuit, and a second inductormagnetically coupled to the first inductor to provide negative feedbackto linearize the low noise amplifier 32. The low noise amplifier 32 isan example of the low noise amplifier 6 discussed above. The low noiseamplifier 32 can include any suitable combination of features discussedin Section I.

FIG. 17 is a cross section of a packaged module 90 that includes anintegrated circuit 81, a crystal 82 vertically integrated with theintegrated circuit 81, and an other integrated circuit 83′ that includesa low noise amplifier 37 and an overload protection circuit 38 accordingto an embodiment. The packaged module 90 includes a package substrate84, a first integrated circuit 81 supported by the package substrate 84,and a crystal 82 supported by the package substrate 84. The firstintegrated circuit 81 is disposed between the crystal 82 and the packagesubstrate 84. The packaged module 90 also includes a second integratedcircuit 83′ supported by the package substrate 84. The package substrate84 can include one or more suitable features discussed in Section VIII.The first integrated circuit 81 can include one or more suitablefeatures discussed in Section VIII. The crystal 82 can include one ormore suitable features discussed in Section VIII. The second integratedcircuit 83′ is not necessarily drawn to scale. The second integratedcircuit 83′ can include any suitable front end circuitry discussedherein. As illustrated, the second integrated circuit 83′ includes anantenna-side switch 47, a low noise amplifier 37 including an inputelectrically coupled to the antenna-side switch 47, and an overloadprotection circuit 38 configured to adjust an impedance of theantenna-side switch 47 based on a signal level of the low noiseamplifier 37. The low noise amplifier 37 is an example of the low noiseamplifier 6 discussed above. The antenna-side switch 47 is an example ofthe antenna-side switch 2 discussed above. The low noise amplifier 37and/or the overload protection circuit 38 and/or the antenna-side switch47 can include any suitable combination of features discussed in SectionII.

FIG. 18 is a cross section of a packaged module 92 that an integratedcircuit 81, a crystal 82 vertically integrated with the integratedcircuit 81, and an other integrated circuit 83″ that includes amulti-mode power amplifier 31 according to an embodiment. The packagedmodule 92 includes a package substrate 84, a first integrated circuit 81supported by the package substrate 84, and a crystal 82 supported by thepackage substrate 84. The first integrated circuit 81 is disposedbetween the crystal 82 and the package substrate 84. The packaged module92 also includes a second integrated circuit 83″ supported by thepackage substrate 84. The package substrate 84 can include one or moresuitable features discussed in Section VIII. The first integratedcircuit 81 can include one or more suitable features discussed inSection VIII. The crystal 82 can include one or more suitable featuresdiscussed in Section VIII. The second integrated circuit 83″ is notnecessarily drawn to scale. The second integrated circuit 83″ includes amulti-mode power amplifier 31 that includes a stacked output stageincluding a transistor stack of two or more transistors. The multi-modepower amplifier 31 also includes a bias circuit configured to control abias of at least one transistor of the transistor stack based on a modeof the multi-mode power amplifier. The multi-mode power amplifier 31 isan example of the power amplifier 5 discussed above. The multi-modepower amplifier 31 can include any suitable combination of featuresdiscussed in Section III.

FIG. 19 is a cross section of a packaged module 94 that includes anintegrated circuit 81, a crystal 82 vertically integrated with theintegrated circuit 81, and an other integrated circuit 83′″ thatincludes a power amplifier 35 with an injection-locked oscillator driverstage according to an embodiment. The packaged module 94 includes apackage substrate 84, a first integrated circuit 81 supported by thepackage substrate 84, and a crystal 82 supported by the packagesubstrate 84. The first integrated circuit 81 is disposed between thecrystal 82 and the package substrate 84. The packaged module 92 alsoincludes a second integrated circuit 83′″ supported by the packagesubstrate 84. The package substrate 84 can include one or more suitablefeatures discussed in Section VIII. The first integrated circuit 81 caninclude one or more suitable features discussed in Section VIII. Thecrystal 82 can include one or more suitable features discussed inSection VIII. The second integrated circuit 83′″ is not necessarilydrawn to scale. The second integrated circuit 83′″ includes a poweramplifier 35 with an injection-locked oscillator driver stage. The poweramplifier 35 is an example of the power amplifier 5 discussed above. Thepower amplifier 35 can include any suitable combination of featuresdiscussed in Section IV.

FIG. 20 is a cross section of a packaged module 96 that includes anintegrated circuit 81, a crystal 82 vertically integrated with theintegrated circuit 81, and an other integrated circuit 83′″ thatincludes an overstress protection circuit 97 according to an embodiment.The packaged module 96 includes a package substrate 84, a firstintegrated circuit 81 supported by the package substrate 84, and acrystal 82 supported by the package substrate 84. The first integratedcircuit 81 is disposed between the crystal 82 and the package substrate84. The packaged module 92 also includes a second integrated circuit83′″ supported by the package substrate 84. The package substrate 84 caninclude one or more suitable features discussed in Section VIII. Thefirst integrated circuit 81 can include one or more suitable featuresdiscussed in Section VIII. The crystal 82 can include one or moresuitable features discussed in Section VIII. The second integratedcircuit 83′″ is not necessarily drawn to scale. The second integratedcircuit 83′″ includes an overstress protection circuit 97. The secondintegrated circuit 83′″ can also include a pad and an internal circuitelectrically connected to a signal node. In an embodiment, theoverstress protection circuit 97 includes an overstress sensing circuitelectrically connected between the pad and a first supply node, animpedance element electrically connected between the pad and the signalnode, and a controllable clamp electrically connected between the signalnode and the first supply node. The overstress sensing circuit isconfigured to activate the controllable clamp in response to detectingan electrical overstress event at the pad. The overstress protectioncircuit 97 can include any suitable combination of features discussed inSection V.

Packaged modules can include a crystal assembly. The crystal assemblycan be disposed between an integrated circuit, such as a system on achip (SoC), and a package substrate. This can result in shorter crystaltraces and enable the packaged module to be more physically compact. Thecrystal assembly can include a crystal oscillator within a housing thatalso includes one or more conductive pillars for routing signals fromthe SoC to a package substrate and/or to provide thermal conductivity.Some example packaged modules with a crystal assembly will be describedwith reference to FIGS. 21 to 25.

FIG. 21 is a cross section of a packaged module 100 that includes anintegrated circuit 81, a crystal assembly 102 under the integratedcircuit 81, and an other integrated circuit 83 that includes a low noiseamplifier 32 with magnetically coupled inductors according to anembodiment. The packaged module 100 includes a package substrate 84, afirst integrated circuit 81 supported by the package substrate 84, and acrystal assembly 102 supported by the package substrate 84 and disposedbetween the first integrated circuit 81 and the package substrate 84.The packaged module 100 also includes a second integrated circuit 83supported by the package substrate 84. The second integrated circuit 83is not necessarily drawn to scale. The package substrate 84 can includeone or more suitable features discussed in Section VIII. The firstintegrated circuit 81 can include one or more suitable featuresdiscussed in Section VIII. The crystal assembly 102 can include one ormore suitable features discussed in Section VIII. The second integratedcircuit 83 can include any suitable front end circuitry discussedherein. As illustrated, the second integrated circuit 83 includes a lownoise amplifier 32 that includes a first inductor, an amplificationcircuit, and a second inductor magnetically coupled to the firstinductor to provide negative feedback to linearize the low noiseamplifier 32. The low noise amplifier 32 is an example of the low noiseamplifier 6 discussed above. The low noise amplifier 32 can include anysuitable combination of features discussed in Section I.

FIG. 22 is a cross section of a packaged module 104 that includes anintegrated circuit 81, a crystal assembly 102 under the integratedcircuit 81, and an other integrated circuit 83′ that includes a lownoise amplifier 37 and an overload protection circuit 38 according to anembodiment. The packaged module 104 includes a package substrate 84, afirst integrated circuit 81 supported by the package substrate 84, and acrystal assembly 102 supported by the package substrate 84 and disposedbetween the first integrated circuit 81 and the package substrate 84.The packaged module 104 also includes a second integrated circuit 83′supported by the package substrate 84. The second integrated circuit 83′is not necessarily drawn to scale. The package substrate 84 can includeone or more suitable features discussed in Section VIII. The firstintegrated circuit 81 can include one or more suitable featuresdiscussed in Section VIII. The crystal assembly 102 can include one ormore suitable features discussed in Section VIII. The second integratedcircuit 83′ can include any suitable front end circuitry discussedherein. As illustrated, the second integrated circuit 83′ includes anantenna-side switch 47, a low noise amplifier 37 including an inputelectrically coupled to the antenna-side switch 47, and an overloadprotection circuit 38 configured to adjust an impedance of theantenna-side switch 47 based on a signal level of the low noiseamplifier 37. The low noise amplifier 37 is an example of the low noiseamplifier 6 discussed above. The antenna-side switch 47 is an example ofthe antenna-side switch 2 discussed above. The low noise amplifier 37and/or the overload protection circuit 38 and/or the antenna-side switch47 can include any suitable combination of features discussed in SectionII.

FIG. 23 is a cross section of a packaged module 105 that an integratedcircuit 81, a crystal assembly 102 under the integrated circuit 81, andan other integrated 83″ circuit that includes a multi-mode poweramplifier 31 according to an embodiment. The packaged module 105includes a package substrate 84, a first integrated circuit 81 supportedby the package substrate 84, and a crystal assembly 102 supported by thepackage substrate 84 and disposed between the first integrated circuit81 and the package substrate 84. The packaged module 105 also includes asecond integrated circuit 83″ supported by the package substrate 84. Thepackage substrate 84 can include one or more suitable features discussedin Section VIII. The first integrated circuit 81 can include one or moresuitable features discussed in Section VIII. The crystal assembly 102can include one or more suitable features discussed in Section VIII. Thesecond integrated circuit 83″ is not necessarily drawn to scale. Thesecond integrated circuit 83″ includes a multi-mode power amplifier 31that includes a stacked output stage including a transistor stack of twoor more transistors. The multi-mode power amplifier 31 also includes abias circuit configured to control a bias of at least one transistor ofthe transistor stack based on a mode of the multi-mode power amplifier.The multi-mode power amplifier 31 is an example of the power amplifier 5discussed above. The multi-mode power amplifier 31 can include anysuitable combination of features discussed in Section III.

FIG. 24 is a cross section of a packaged module 106 that includes anintegrated circuit 81, a crystal assembly 102 under the integratedcircuit 81, and an other integrated circuit 83′″ that includes a poweramplifier 35 with an injection-locked oscillator driver stage accordingto an embodiment. The packaged module 106 includes a package substrate84, a first integrated circuit 81 supported by the package substrate 84,and a crystal assembly 102 supported by the package substrate 84 anddisposed between the first integrated circuit 81 and the packagesubstrate 84. The packaged module 106 also includes a second integratedcircuit 83′″ supported by the package substrate 84. The secondintegrated circuit 83′″ is not necessarily drawn to scale. The packagesubstrate 84 can include one or more suitable features discussed inSection VIII. The first integrated circuit 81 can include one or moresuitable features discussed in Section VIII. The crystal assembly 102can include one or more suitable features discussed in Section VIII. Thesecond integrated circuit 83′″ includes a power amplifier 35 with aninjection-locked oscillator driver stage. The power amplifier 35 is anexample of the power amplifier 5 discussed above. The power amplifier 35can include any suitable combination of features discussed in SectionIV.

FIG. 25 is a cross section of a packaged module 108 that includes anintegrated circuit 81, a crystal assembly 102 under the integratedcircuit 81, and an other integrated circuit 83′″ that includes anoverstress protection circuit 97 according to an embodiment. Thepackaged module 108 includes a package substrate 84, a first integratedcircuit 81 supported by the package substrate 84, and a crystal assembly102 supported by the package substrate 84 and disposed between the firstintegrated circuit 81 and the package substrate 84. The packaged module108 also includes a second integrated circuit 83′″ supported by thepackage substrate 84. The second integrated circuit 83′″ is notnecessarily drawn to scale. The package substrate 84 can include one ormore suitable features discussed in Section VIII. The first integratedcircuit 81 can include one or more suitable features discussed inSection VIII. The crystal assembly 102 can include one or more suitablefeatures discussed in Section VIII. The second integrated circuit 83′″includes an overstress protection circuit 97. The second integratedcircuit 83′″ can also include a pad and an internal circuit electricallyconnected to a signal node. In an embodiment, the overstress protectioncircuit 97 includes an overstress sensing circuit electrically connectedbetween the pad and a first supply node, an impedance elementelectrically connected between the pad and the signal node, and acontrollable clamp electrically connected between the signal node andthe first supply node. The overstress sensing circuit is configured toactivate the controllable clamp in response to detecting an electricaloverstress event at the pad. The overstress protection circuit 97 caninclude any suitable combination of features discussed in Section V.

Packaged modules can include a stacked filter assembly. The stackedfilter assembly can be arranged so as to reduce a footprint and/orphysical size of a packaged module. A stacked filter assembly caninclude passive components packaged as surface mount devices (e.g., oneor more capacitors, one or more inductors, and/or one or more resistors)and arranged as a stack. Some example packaged modules with a stackedfilter assembly will be described with reference to FIGS. 26 to 30.

FIG. 26 is a block diagram of a packaged module 110 that includes astacked filter assembly 112 and a low noise amplifier 32 withmagnetically coupled inductors according to an embodiment. The packagedmodule 110 includes a package substrate 84, a front end integratedcircuit 83 supported by the package substrate 84, and a stacked filterassembly 112 supported by the package substrate 84. The stacked filterassembly 112 can filter a signal associated with the front endintegrated circuit 83. The packaged module 110 also includes an otherintegrated circuit 81 supported by the package substrate 84. The packagesubstrate 84 can include one or more suitable features discussed inSection VIII. The other integrated circuit 81 can include one or moresuitable features discussed in Section VIII. The stacked filter assembly112 can include one or more suitable features discussed in Section VIII.The front end integrated circuit 83 can include any suitable front endcircuitry discussed herein. As illustrated, the front end integratedcircuit 83 includes a low noise amplifier 32 that includes a firstinductor, an amplification circuit, and a second inductor magneticallycoupled to the first inductor to provide negative feedback to linearizethe low noise amplifier 32. The low noise amplifier 32 is an example ofthe low noise amplifier 6 discussed above. The low noise amplifier 32can include any suitable combination of features discussed in Section I.

FIG. 27 is a block diagram of a packaged module 114 that includes astacked filter assembly 112 and a low noise amplifier 37 and an overloadprotection circuit 38 according to an embodiment. The packaged module114 includes a package substrate 84, a front end integrated circuit 83′supported by the package substrate 84, and a stacked filter assembly 112supported by the package substrate 84. The stacked filter assembly 112can filter a signal associated with the front end integrated circuit83′. The packaged module 110 also includes an other integrated circuit81 supported by the package substrate 84. The package substrate 84 caninclude one or more suitable features discussed in Section VIII. Theother integrated circuit 81 can include one or more suitable featuresdiscussed in Section VIII. The stacked filter assembly 112 can includeone or more suitable features discussed in Section VIII. As illustrated,the front end integrated circuit 83′ includes an antenna-side switch 47,a low noise amplifier 37 including an input electrically coupled to theantenna-side switch 47, and an overload protection circuit 38 configuredto adjust an impedance of the antenna-side switch 47 based on a signallevel of the low noise amplifier 37. The low noise amplifier 37 is anexample of the low noise amplifier 6 discussed above. The antenna-sideswitch 47 is an example of the antenna-side switch 2 discussed above.The low noise amplifier 37 and/or the overload protection circuit 38and/or the antenna-side switch 47 can include any suitable combinationof features discussed in Section II.

FIG. 28 is a block diagram of a packaged module 115 that includes astacked filter assembly 112 and a multi-mode power amplifier 31according to an embodiment. The packaged module 115 includes a packagesubstrate 84, a front end integrated circuit 83″ supported by thepackage substrate 84, and a stacked filter assembly 112 supported by thepackage substrate 84. The stacked filter assembly 112 can filter asignal associated with the front end integrated circuit 83″. Thepackaged module 115 also includes an other integrated circuit 81supported by the package substrate 84. The package substrate 84 caninclude one or more suitable features discussed in Section VIII. Theother integrated circuit 81 can include one or more suitable featuresdiscussed in Section VIII. The stacked filter assembly 112 can includeone or more suitable features discussed in Section VIII. The front endintegrated circuit 83″ includes a multi-mode power amplifier 31 thatincludes a stacked output stage including a transistor stack of two ormore transistors. The multi-mode power amplifier 31 also includes a biascircuit configured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifier. Themulti-mode power amplifier 31 is an example of the power amplifier 5discussed above. The multi-mode power amplifier 31 can include anysuitable combination of features discussed in Section III.

FIG. 29 is a block diagram of a packaged module 116 that includes astacked filter assembly 112 and a power amplifier 35 with aninjection-locked oscillator driver stage according to an embodiment. Thepackaged module 116 includes a package substrate 84, a front endintegrated circuit 83″ supported by the package substrate 84, and astacked filter assembly 112 supported by the package substrate 84. Thestacked filter assembly 112 can filter a signal associated with thefront end integrated circuit 83″. The packaged module 116 also includesan other integrated circuit 81 supported by the package substrate 84.The package substrate 84 can include one or more suitable featuresdiscussed in Section VIII. The other integrated circuit 81 can includeone or more suitable features discussed in Section VIII. The stackedfilter assembly 112 can include one or more suitable features discussedin Section VIII. The front end integrated circuit 83″ includes a poweramplifier 35 with an injection-locked oscillator driver stage. The poweramplifier 35 is an example of the power amplifier 5 discussed above. Thepower amplifier 35 can include any suitable combination of featuresdiscussed in Section IV.

FIG. 30 is a block diagram of a packaged module 118 that includes astacked filter assembly 112 and an overstress protection circuit 97according to an embodiment. The packaged module 118 includes a packagesubstrate 84, a front end integrated circuit 83′″ supported by thepackage substrate 84, and a stacked filter assembly 112 supported by thepackage substrate 84. The stacked filter assembly 112 can filter asignal associated with the front end integrated circuit 83″″. Thepackaged module 118 also includes an other integrated circuit 81supported by the package substrate 84. The package substrate 84 caninclude one or more suitable features discussed in Section VIII. Theother integrated circuit 81 can include one or more suitable featuresdiscussed in Section VIII. The stacked filter assembly 112 can includeone or more suitable features discussed in Section VIII. The front endintegrated circuit 83′″ includes an overstress protection circuit 97.The front end integrated circuit 83′″ can also include a pad and aninternal circuit electrically connected to a signal node. In anembodiment, the overstress protection circuit 97 includes an overstresssensing circuit electrically connected between the pad and a firstsupply node, an impedance element electrically connected between the padand the signal node, and a controllable clamp electrically connectedbetween the signal node and the first supply node. The overstresssensing circuit is configured to activate the controllable clamp inresponse to detecting an electrical overstress event at the pad. Theoverstress protection circuit 97 can include any suitable combination offeatures discussed in Section V.

Internet of Things Applications

One example application of the front end systems herein is to enablevarious objects with wireless connectivity, such as for Internet ofthings (IoT). IoT refers to a network of objects or things, such asdevices, vehicles, and/or other items that are embedded with electronicsthat enable the objects to collect and exchange data (for instance,machine-to-machine communications) and/or to be remotely sensed and/orcontrolled. The front end systems herein can be used to enable wirelessconnectivity of various objects, thereby allowing such objects tocommunicate in an IoT network. The front end systems discussed hereincan be implemented in IoT applications to enable wireless connectivityto expand the way consumers manage information and their environment.Such front end systems can enable the new and emerging IoT applications,which can bring people and things closer to vital information whereverit is desired. Although IoT is one example application of front endsystems herein, the teachings herein are applicable to a wide range oftechnologies and applications. Some example IoT applications will now bediscussed.

IoT devices can be implemented in automotive systems. From telematics toinfotainment systems, lighting, remote keyless entry, collisionavoidance platforms, toll transponders, video displays, vehicle trackingtools, and the like, front end systems in accordance with any suitableprinciples and advantages discussed herein can help enable convenienceand safety features for the connected vehicle.

IoT devices can be implemented in connected home environments. Front endsystems in accordance with any suitable principles and advantagesdiscussed herein can allow homeowners greater control over their homeenvironment. IoT devices can be implemented in a host of devicesincluding smart thermostats, security systems, sensors, light switches,smoke and carbon monoxide alarms, routers, high definition televisions,gaming consoles and much more.

IoT devices can be implemented in industrial contexts. From smart cityapplications to factory automation, building controls, commercialaircraft, vehicle tracking, smart metering, LED lighting, securitycameras, and smart agriculture functions, front ends systems inaccordance with any suitable principles and advantages discussed hereincan enable these applications and meet specifications.

IoT devices can be implemented in machine-to-machine contexts. IoTdevices can enable machine-to-machine communications that can transformthe way organizations do business. From manufacturing automation totelemetry, remote control devices, and asset management, front endsystems discussed herein can provide cellular, short-range, and globalpositioning solutions that support a wide range of machine-to-machineapplications.

IoT devices can be implemented in medical applications. Front endsystems in accordance with any suitable principles and advantagesdiscussed herein can enable medical devices and the communication ofinformation that is improving the care of millions of people worldwide.Front end systems in accordance with any suitable principles andadvantages discussed herein can be integrated into product designs thatenable the miniaturization of medical devices and enhance datatransmission. Amplifiers, such as power amplifiers and low noiseamplifiers, in accordance with any suitable principles and advantagesdiscussed herein can be implemented in medical instruments.

IoT devices can be implemented in mobile devices. The communicationlandscape has changed in recent years as consumers increasingly seek tobe connected everywhere and all the time. Front end systems inaccordance with any suitable principles and advantages discussed hereincan be compact, energy and cost efficient, meeting size and performanceconstraints, while enabling a great consumer experience. Wireless mobiledevices, such as smartphones, tablets and WLAN systems, can include afront end system in accordance with any suitable principles andadvantages discussed herein.

IoT devices can be implemented in smart energy applications. Utilitycompanies are modernizing their systems using computer-based remotecontrol and automation that involves two-way communication. Somebenefits to utilities and consumers include optimized energy efficiency,leveling and load balancing on the smart grid. Front end systems inaccordance with any suitable principles and advantages discussed hereincan be implemented in smart meters, smart thermostats, in-home displays,ZigBee/802.15.4, Bluetooth, and Bluetooth low energy applications.

IoT devices can be implemented in wearable devices. Wearable devices,such as smartwatches, smart eyewear, fitness trackers and healthmonitors, can include front end systems in accordance with any suitableprinciples and advantages discussed herein to enable relatively smallform factor solutions that consume relatively low power and enablealways on connectivity. This can allow applications to run in thebackground for lengthy periods of time without a battery recharge, forexample.

Any suitable principles and advantages discussed herein can implementedin an IoT network, IoT object, a vehicle, industrial equipment, acorresponding front end system, a corresponding circuit board, the like,or any suitable combination thereof. Some examples will now bediscussed.

FIG. 31 is a schematic diagram of one example of an IoT network 200. TheIoT network 200 includes a smart home 201, a smart vehicle 202, awearable 203, a mobile device 204, a base station 205, a smart hospital206, a smart factory 207, and a smart satellite 208. One or more of theIoT-enabled objects of FIG. 31 can include a front end system, such as afront end module and/or front-end integrated circuit, implemented inaccordance with the teachings herein.

The smart home 201 is depicted as including a wide variety ofIoT-enabled objects, including an IoT-enabled router 211, an IoT-enabledthermostat 212, an IoT-enabled meter 213, IoT-enabled laptop 214, and anIoT-enabled television 215. Although various examples of IoT-enableobjects for a smart home are shown, a smart home can include a widevariety of IoT-enabled objects. Examples of such IoT-enabled objectsinclude, but are not limited to, an IoT-enabled computer, an IoT-enabledlaptop, an IoT-enabled tablet, an IoT-enabled computer monitor, anIoT-enabled television, an IoT-enabled media system, an IoT-enabledgaming system, an IoT-enabled camcorder, an IoT-enabled camera, anIoT-enabled modem, an IoT-enabled router, an IoT-enabled kitchenappliance, an IoT-enabled telephone, an IoT-enabled air conditioner, anIoT-enabled washer, an IoT-enabled dryer, an IoT-enabled copier, anIoT-enabled facsimile machine, an IoT-enabled scanner, an IoT-enabledprinter, an IoT-enabled scale, an IoT-enabled home assistant (forinstance, a voice-controlled assistant device), an IoT-enabled securitysystem, an IoT-enabled thermostat, an IoT-enabled smoke detector, anIoT-enabled garage door, an IoT-enabled lock, an IoT-enabled sprinkler,an IoT-enabled water heater, and/or an IoT-enabled light.

As shown in FIG. 31, the smart vehicle 202 also operates in the IoTnetwork 200. The smart vehicle 202 can include a wide variety ofIoT-enabled objects, including, but not limited to, an IoT-enabledinfotainment system, an IoT-enabled lighting system, an IoT-enabledtemperature control system, an IoT-enabled lock, an IoT-enabledignition, an IoT-enabled collision avoidance system, an IoT-enabled tolltransponder, and/or an IoT-enabled vehicle tracking system. In certainimplementations, the smart vehicle 202 can communicate with other smartvehicles to thereby provide vehicle-to-vehicle (V2V) communications.Furthermore, in certain implementations the smart vehicle 202 canoperate using vehicle-to-everything (V2X) communications, therebycommunicating with traffic lights, toll gates, and/or other IoT-enabledobjects.

The wearable 203 of FIG. 31 is also IoT-enabled. Examples of IoT-enabledwearables include, but are not limited to, an IoT-enabled watch, anIoT-enabled eyewear, an IoT-enabled fitness tracker, and/or anIoT-enabled biometric device.

The IoT network 200 also includes the mobile device 204 and base station205. Thus, in certain implementations user equipment (UE) and/or basestations of a cellular network can operate in an IoT network and beIoT-enabled. Furthermore, a wide variety of IoT-enabled objects cancommunication using existing network infrastructure, such as cellularinfrastructure.

With continuing reference to FIG. 31, IoT is not only applicable toconsumer devices and objects, but also to other applications, such asmedical, commercial, industrial, aerospace, and/or defense applications.For example, the smart hospital 206 can include a wide variety ofIoT-enabled medical equipment and/or the smart factory 207 can include awide variety of IoT-enabled industrial equipment. Furthermore,airplanes, satellites, and/or aerospace equipment can also be connectedto an IoT network. Other examples of IoT applications include, but arenot limited to, asset tracking, fleet management, digital signage, smartvending, environmental monitoring, city infrastructure (for instance,smart street lighting), toll collection, and/or point-of-sale.

Although various examples of IoT-enabled objects are illustrated in FIG.31, an IoT network can include a wide variety of types of objects.Furthermore, any number of such objects can be present in an IoTnetwork. For instance, an IoT network can include millions or billionsof IoT-enable objects or things.

IoT-enabled objects can communicate using a wide variety ofcommunication technologies, including, but not limited to, Bluetooth,ZigBee, Z-Wave, 6LowPAN, Thread, Wi-Fi, NFC, Sigfox, Neul, and/orLoRaWAN technologies. Furthermore, certain IoT-enabled objects cancommunicate using cellular infrastructure, for instance, using 2G, 3G,4G (including LTE, LTE-Advanced, and/or LTE-Advanced Pro), and/or 5Gtechnologies.

FIG. 32A is a schematic diagram of one example of an IoT-enabled watch300. The IoT-enabled watch 300 illustrates one example of a smartwearable that can include a front end system implemented in accordancewith one or more features disclosed herein.

FIG. 32B is a schematic diagram of one example of a front end system 301for an IoT-enabled object, such as the IoT-enabled watch 300 of FIG.32A. The front end system 301 includes a first transceiver-side switch303, a second transceiver-side switch 304, a first antenna-side switch305, a second antenna-side switch 306, a first power amplifier 307, asecond power amplifier 308, a duplexer 311, a directional coupler 312, atermination impedance 313, a first band selection filter 315, a secondband selection filter 316, and a third band selection filter 317.

In the illustrated embodiment, the first transceiver-side switch 303selects between a Band 26 transmit input pin (B26 TX IN) and a Band 13transmit input pin (B13 TX IN). The second transceiver-side switch 303controls connection of the output of the first power amplifier 307 tothe first band selection filter 315 or the first band selection filter316. Thus, the first power amplifier 307 selectively amplifies Band 26or Band 13, in this example. Additionally, the second power amplifier308 amplifies a Band 12 transmit input pin (B12 TX IN). After suitablefiltering by the band selection filters 315-317, the second antenna-sideswitch 306 selects a desired transmit signal for providing to an antennapin (ANT) via the duplexer 311 and the directional coupler 312. As shownin FIG. 32B, the directional coupler 312 is terminated by thetermination impedance 313. Additionally, the first antenna-side switch305 provides a signal received on the antenna pin (ANT) to a desiredreceive output pin (four in this example) of the front end system 301.The illustrated front end system 301 also includes various additionalpins to provide additional functionality, such as enhanced monitoring oftransmit power. For instance, front end system 301 includes adirectional coupler output pin (CPL), and feedback pins (B12 RX, B13 RX,and B26 RX) for providing feedback signals associated with transmitsignals (for Band 12, Band 13, and Band 26, respectively) generated bythe power amplifiers.

The front end system 301 can incorporate one or more features describedin the sections herein.

FIG. 33A is a schematic diagram of one example of IoT-enabled vehicles321 a-321 d. Each of the IoT-enabled vehicles 321 a-321 d includes afront end system for enabling wireless vehicle-to-vehiclecommunications. The IoT-enabled vehicles 321 a-321 d can include a frontend system implemented in accordance with one or more features disclosedherein.

FIG. 33B is a schematic diagram of another example of a front end system325 for an IoT-enabled object. The front end system 325 includes anantenna-side switch 331, a bypass switch 332, an LNA 333, and a bias andlogic circuit 334.

The front end system 325 includes control pins (C0 and C1) forcontrolling the front end system 325 and a supply voltage pin (VDD) forpowering the front end system 325. The antenna-side switch 331selectively connects an antenna pin (ANT) to a transmit signal pin(TX_IN) or a receive signal pin (RX_OUT). The LNA 333 includes an inputconnected to an LNA input pin (LNA_IN) and an output connected to theLNA output pin (LNA_OUT). The LNA 333 is selectively bypassed by thebypass switch 332. Using external conductors and components, the LNAinput pin (LNA_IN) can be connected to the receive signal pin (RX_OUT)either directly or indirectly (for instance, via a filter or othercomponents). Furthermore, an external power amplifier can provide atransmit signal to the transmit signal pin (TX_IN).

The front end system 325 can incorporate one or more features describedin the sections herein.

FIG. 34A is a schematic diagram of one example of IoT-enabled industrialequipment 340. In the illustrated embodiment, the IoT-enabled industrialequipment 340 includes heliostats 341 for reflecting light to a solarreceiver and turbine 342. The IoT-enabled industrial equipment 340 caninclude one or more front end systems for a variety of purposes, such asproviding angular positional control of the heliostats 341 to controlconcentration of solar energy directed toward the solar receiver andturbine 342. The IoT-enabled industrial equipment 340 can include afront end system implemented in accordance with one or more featuresdisclosed herein.

FIG. 34B is a schematic diagram of another example of a front end system345 for an IoT-enabled object, such as the IoT-enabled industrialequipment 340 of FIG. 34A.

The front end system 345 includes a logic control circuit 350, atransceiver DC blocking capacitor 351, a first antenna DC blockingcapacitor 352, a second antenna DC blocking capacitor 353, an LNA 354, apower amplifier 356, an antenna-side switch 357, a bypass switch 358,and a transceiver-side switch 359.

The front end system 345 includes control pins (CPS, CTX, CSD, ANT SEL)for controlling the front end system 345. The antenna-side switch 357selectively connects either a first antenna pin (ANT1) or a secondantenna pin (ANT2) to either an output of the power amplifier 356 or thebypass switch 358/input to the LNA 354. Additionally, the bypass switch358 selectively bypasses the LNA 354. Furthermore, the transceiver-sideswitch 359 selectively connected the transceiver pin (TR) to either aninput of the power amplifier 356 or the bypass switch 358/output to theLNA 354. The DC blocking capacitors 351-353 serve to provide DC blockingto provide enhanced flexibility in controlling internal DC biasing ofthe front end system 345.

The front end system 345 can incorporate one or more features describedin the sections herein.

FIG. 35A is a schematic diagram of one example of an IoT-enabled lock360. The IoT-enabled lock 360 illustrates one example of an IoT-enabledobject that can include a front end system implemented in accordancewith one or more features disclosed herein.

FIG. 35B is a schematic diagram of one example of a circuit board 361for the IoT-enabled lock 360 of FIG. 35A. The circuit board 361 includesa front end system 362, which can incorporate one or more featuresdescribed in the sections herein.

FIG. 36A is a schematic diagram of one example of IoT-enabled thermostat370. The IoT-enabled thermostat 370 illustrates another example of anIoT-enabled object that can include a front end system implemented inaccordance with one or more features disclosed herein.

FIG. 36B is a schematic diagram of one example of a circuit board 371for the IoT-enabled thermostat 370 of FIG. 36A. The circuit board 371includes a front end system 372, which can incorporate one or morefeatures described in the sections herein.

FIG. 37A is a schematic diagram of one example of IoT-enabled light 380.

The IoT-enabled light 380 illustrates another example of an IoT-enabledobject that can include a front end system implemented in accordancewith one or more features disclosed herein.

FIG. 37B is a schematic diagram of one example of a circuit board 381for the IoT-enabled light 380 of FIG. 37A. FIG. 37B also depicts a baseportion of the IoT-enabled light 380 for housing the circuit board 381.The circuit board 381 includes a front end system 382, which canincorporate one or more features described in the sections herein.

Radio Frequency Systems

FIGS. 38A-38F illustrates various schematic block diagrams of examplesof radio frequency systems that include a front end system, such as afront end module or front end integrated circuit. The radio frequencysystems of FIGS. 38A-38F can incorporate one or more features describedin the sections herein. In certain implementations, a radio frequencysystem, such as any of the radio frequency systems of FIGS. 38A-38F, isimplemented on a circuit board (for instance, a printed circuit board(PCB)) of a wireless communication device, such as a mobile phone, atablet, a base station, a network access point, customer-premisesequipment (CPE), an IoT-enabled object, a laptop, and/or a wearableelectronic device.

FIG. 38A illustrates a schematic block diagram of one example of a radiofrequency system 500. The radio frequency system 500 includes an antenna501, a front end system 10, and a transceiver 505. As was discussedabove, the front end system 10 can incorporate one or more featuresdescribed in the sections herein.

The antenna 501 operates to wirelessly transmit RF signals received viathe antenna-side switch 2. The RF transmit signals can include RFsignals generated by the power amplifier 5 and/or RF signals sent viathe bypass circuit 4. The antenna 501 also operates to wirelesslyreceive RF signals, which can be provided to the LNA 6 and/or the bypasscircuit 4 via the antenna-side switch 2. Although an example where acommon antenna is used for transmitting and receiving signals, theteachings herein are also applicable to implementations using separateantennas for transmission and reception. Example implementations of theantenna 501 include, but are not limited to, a patch antenna, a dipoleantenna, a ceramic resonator, a stamped metal antenna, a laser directstructuring antenna, and/or a multi-layered antenna.

The transceiver 505 operates to provide RF signals to thetransceiver-side switch 3 for transmission and/or to receive RF signalsfrom the transceiver-side switch 3. The transceiver 505 can communicateusing a wide variety communication technologies, including, but notlimited to, one or more of 2G, 3G, 4G (including LTE, LTE-Advanced,and/or LTE-Advanced Pro), 5G, WLAN (for instance, Wi-Fi), WPAN (forinstance, Bluetooth and/or ZigBee), WMAN (for instance, WiMAX), and/orGPS technologies.

FIG. 38B illustrates a schematic block diagram of another example of aradio frequency system 506. The radio frequency system 506 includes afront end system 20 and a transceiver 505. As was discussed above, thefront end system 20 can incorporate one or more features described inthe sections herein.

FIG. 38C illustrates a schematic block diagram of another example of aradio frequency system 510. The radio frequency system 510 includes anantenna 501, a front end system 511, and a transceiver 505. The frontend system 511 of FIG. 38C is similar to the front end system 10 of FIG.38A, except that the bypass path including the bypass circuit 4 has beenomitted and the antenna-side switch 2′ and the transceiver-side switch3′ include one less throw. Thus, the antenna-side switch 2′ isconfigured to selectively electrically connect the antenna 501 to eitheran input to the LNA 6 or an output of the power amplifier 5.Additionally, the transceiver-side switch 3′ is configured toselectively electrically connect the transceiver 505 to either an outputto the LNA 6 or an input of the power amplifier 5.

FIG. 38D illustrates a schematic block diagram of another example of aradio frequency system 512. The radio frequency system 512 includes afirst antenna 501, a second antenna 502, a front end system 514, and atransceiver 505. The front end system 514 of FIG. 38D is similar to thefront end system 10 of FIG. 38A, except that the antenna-side switch 2″includes an additional throw to provide connectivity to an additionalantenna. Thus, the bypass circuit 4, the power amplifier 5, and/or theLNA 6 can be selectively electrically connected to the first antenna 501and/or the second antenna 502. Although an example of a radio frequencysystem with two antennas is shown, a radio frequency system can includemore or fewer antennas.

Multiple antennas can be included in a radio frequency system for a widevariety of reasons. In one example, the first antenna 501 and the secondantenna 502 correspond to a transmit antenna and a receive antenna,respectively. In a second example, the first antenna 501 and the secondantenna 502 are used for transmitting and/or receiving signalsassociated with different frequency ranges (for instance, differentbands). In a third example, the first antenna 501 and the second antenna502 support diversity communications, such as multiple-inputmultiple-output (MIMO) communications and/or switched diversitycommunications. In a fourth example, the first antenna 501 and thesecond antenna 502 support beamforming of transmit and/or receive signalbeams.

FIG. 38E illustrates a schematic block diagram of another example of aradio frequency system 520. The radio frequency system 520 includes anantenna 501, a front end system 524, and a transceiver 505. The frontend system 524 of FIG. 38E is similar to the front end system 10 of FIG.38A, except that the transmit path including the power amplifier 5 hasbeen omitted and the antenna-side switch 2′ and the transceiver-sideswitch 3′ include one less throw. Thus, the antenna-side switch 2′ isconfigured to selectively electrically connect the antenna 501 to eitheran input to the LNA 6 or the bypass circuit 4. Additionally, thetransceiver-side switch 3′ is configured to selectively electricallyconnect the transceiver 505 to either an output to the LNA 6 or thebypass circuit 4.

FIG. 38F illustrates a schematic block diagram of another example of aradio frequency system 530. The radio frequency system 530 includes apower amplifier 5, an antenna 501, a front end system 534, and atransceiver 505. The front end system 534 of FIG. 38F is similar to thefront end system 10 of FIG. 38A, except that the power amplifier 5 hasbeen omitted and the front end system 534 includes input/output portsfor coupling to throws of the antenna-side switch 2 and transceiver-sideswitch 3. A power amplifier 5 external to the front end system 534 canbe electrically connected between these input/output ports such that thepower amplifier 5 is included in the transmit signal path between theantenna-side switch 2 and transceiver-side switch 3. The power amplifier5 can be included in a different packaged module and/or embodied on adifferent die than the illustrated elements of the front end system 534.

Wireless Communication Devices

FIG. 39A is a schematic diagram of one example of a wirelesscommunication device 650. The wireless communication device 650 includesa first antenna 641, a wireless personal area network (WPAN) system 651,a transceiver 652, a processor 653, a memory 654, a power managementblock 655, a second antenna 656, and a front end system 657.

Any of the suitable combination of features disclosed herein can beimplemented in the wireless communication device 650. For example, theWPAN system 651 and/or the front end system 657 can be implemented usingany of the features described above and/or in the sections below.

The WPAN system 651 is a front end system configured for processingradio frequency signals associated with personal area networks (PANs).The WPAN system 651 can be configured to transmit and receive signalsassociated with one or more WPAN communication standards, such assignals associated with one or more of Bluetooth, ZigBee, Z-Wave,Wireless USB, INSTEON, IrDA, or Body Area Network. In anotherembodiment, a wireless communication device can include a wireless localarea network (WLAN) system in place of the illustrated WPAN system, andthe WLAN system can process Wi-Fi signals.

FIG. 39B is a schematic diagram of another example of a wirelesscommunication device 660. The illustrated wireless communication device660 of FIG. 39B is a device configured to communicate over a PAN. Thiswireless communication device 660 can be relatively less complex thanthe wireless communication device 650 of FIG. 8A. As illustrated, thewireless communication device 660 includes an antenna 641, a WPAN system651, a transceiver 662, a processor 653, and a memory 654. The WPANsystem 660 can include any suitable combination of features disclosedherein. For example, the WPAN system 651 can be implemented using any ofthe features described above and/or in the sections below.

FIG. 39C is a schematic diagram of another example of a wirelesscommunication device 800. The wireless communication device 800 includesa baseband system 801, a transceiver 802, a front-end system 803, one ormore antennas 804, a power management system 805, a memory 806, a userinterface 807, and a battery 808.

The wireless communication device 800 can be used communicate using awide variety of communications technologies, including, but not limitedto, 2G, 3G, 4G (including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G,WLAN (for instance, Wi-Fi), WPAN (for instance, Bluetooth and ZigBee),WMAN (for instance, WiMAX), and/or GPS technologies.

The transceiver 802 generates RF signals for transmission and processesincoming RF signals received from the antennas 804. It will beunderstood that various functionalities associated with the transmissionand receiving of RF signals can be achieved by one or more componentsthat are collectively represented in FIG. 39C as the transceiver 802. Inone example, separate components (for instance, separate circuits ordies) can be provided for handling certain types of RF signals.

The front-end system 803 aids in conditioning signals transmitted toand/or received from the antennas 804. In the illustrated embodiment,the front-end system 803 includes one or more power amplifiers (PAs)811, one or more low noise amplifiers (LNAs) 812, one or more filters813, one or more switches 814, and one or more duplexers 815. However,other implementations are possible.

For example, the front-end system 803 can provide a number offunctionalities, including, but not limited to, amplifying signals fortransmission, amplifying received signals, filtering signals, switchingbetween different bands, switching between different power modes,switching between transmission and receiving modes, duplexing ofsignals, multiplexing of signals (for instance, diplexing ortriplexing), or some combination thereof.

Any of the suitable combination of features disclosed herein can beimplemented in the wireless communication device 800. For example, thefront end system 803 can be implemented using any of the featuresdescribed above and/or in the sections below.

In certain implementations, the wireless communication device 800supports carrier aggregation, thereby providing flexibility to increasepeak data rates. Carrier aggregation can be used for both FrequencyDivision Duplexing (FDD) and Time Division Duplexing (TDD), and may beused to aggregate a plurality of carriers or channels. Carrieraggregation includes contiguous aggregation, in which contiguouscarriers within the same operating frequency band are aggregated.Carrier aggregation can also be non-contiguous, and can include carriersseparated in frequency within a common band or in different bands.

The antennas 804 can include antennas used for a wide variety of typesof communications. For example, the antennas 804 can include antennasfor transmitting and/or receiving signals associated with a wide varietyof frequencies and communications standards.

In certain implementations, the antennas 804 support MIMO communicationsand/or switched diversity communications. For example, MIMOcommunications use multiple antennas for communicating multiple datastreams over a single radio frequency channel. MIMO communicationsbenefit from higher signal to noise ratio, improved coding, and/orreduced signal interference due to spatial multiplexing differences ofthe radio environment. Switched diversity refers to communications inwhich a particular antenna is selected for operation at a particulartime. For example, a switch can be used to select a particular antennafrom a group of antennas based on a variety of factors, such as anobserved bit error rate and/or a signal strength indicator.

The wireless communication device 800 can operate with beamforming incertain implementations. For example, the front-end system 803 caninclude phase shifters having variable phase controlled by thetransceiver 802. Additionally, the phase shifters are controlled toprovide beam formation and directivity for transmission and/or receptionof signals using the antennas 804. For example, in the context of signaltransmission, the phases of the transmit signals provided to theantennas 804 are controlled such that radiated signals from the antennas804 combine using constructive and destructive interference to generatean aggregate transmit signal exhibiting beam-like qualities with moresignal strength propagating in a given direction. In the context ofsignal reception, the phases are controlled such that more signal energyis received when the signal is arriving to the antennas 804 from aparticular direction. In certain implementations, the antennas 804include one or more arrays of antenna elements to enhance beamforming.

The baseband system 801 is coupled to the user interface 807 tofacilitate processing of various user input and output (I/O), such asvoice and data. The baseband system 801 provides the transceiver 802with digital representations of transmit signals, which the transceiver802 processes to generate RF signals for transmission. The basebandsystem 801 also processes digital representations of received signalsprovided by the transceiver 802. As shown in FIG. 39C, the basebandsystem 801 is coupled to the memory 806 of facilitate operation of thewireless communication device 800.

The memory 806 can be used for a wide variety of purposes, such asstoring data and/or instructions to facilitate the operation of thewireless communication device 800 and/or to provide storage of userinformation.

The power management system 805 provides a number of power managementfunctions of the wireless communication device 800. In certainimplementations, the power management system 805 includes a PA supplycontrol circuit that controls the supply voltages of the poweramplifiers 811. For example, the power management system 805 can beconfigured to change the supply voltage(s) provided to one or more ofthe power amplifiers 811 to improve efficiency, such as power addedefficiency (PAE).

As shown in FIG. 39C, the power management system 805 receives a batteryvoltage from the battery 808. The battery 808 can be any suitablebattery for use in the wireless communication device 800, including, forexample, a lithium-ion battery.

Section I—Low Noise Amplifier with Impedance Transformation Circuit

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to a low noise amplifier (LNA) with animpedance transformation circuit. The impedance transformation circuitincludes magnetically coupled inductors to linearize the LNA. Asindicated above, aspects of this section may be combined with otheraspects of one or more other sections to further improve the performanceof front end systems and related devices, integrated circuits, modules,and methods in which they are employed.

There are several performance parameters for any given low noiseamplifier design to satisfy simultaneously. Supply current for a lownoise amplifier is often pre-determined. In such circumstances, thereare relatively few variables that can be manipulated to set the overallbehavior of the circuit. This section provides one more controllingvariable to set the overall performance of the circuit. In particular,linearity can be improved by implementing features of this section.

In an LNA, linearity can be a significant parameter. It can be desirablefor an LNA to have a relatively high linearity. Linearity can bemeasured by a 1 dB compression point and/or a 3rd order intermodulation.Accordingly, a 1 dB compression point and/or a 3rd order intermodulationof an LNA can be significant. Specifications for LNAs and other circuitsare specifying higher linearity with lower supply current. This trend isexpected to continue. Such specifications can be challenging to meetwhile also meeting other performance specifications. Accordingly, thereis a need for LNAs with improved linearity.

This section provides a new way to control the input match of an LNA,and in such a way the linearity of the LNA can be improved. Forinstance, using the principles and advantages discussed in this section,the 1 dB compression point and 3rd order intermodulation can beimproved. This section provides circuits that can extend inductivelydegenerated amplifier concepts such that both self and mutual inductanceeffects can improve linearity of an LNA, instead of only self-inductivedegeneration.

An LNA can include an inductively degenerated common source or commonemitter amplifying device. The inductive degeneration can linearize sucha circuit. In addition, the degeneration inductor can set the inputimpedance of the circuit in conjunction with the size and bias currentof the amplifying device. A series input matching inductor at the inputcan be included to achieve a desired input impedance and obtain arelatively good input match.

Aspects of this disclosure relate to an LNA with magnetic couplingbetween a degeneration inductor (e.g., a source degeneration inductor oran emitter degeneration inductor) and a series input inductor. Thesemagnetically coupled inductors can in effect provide a transformer, witha primary winding in series with the input and a secondary windingelectrically connected where the degeneration inductor is electricallyconnected to the amplifying device (e.g., at the source of a fieldeffect transistor amplifying device or at the emitter of a bipolartransistor amplifying device). The phase of the magnetic coupling can besignificant. This phase is indicated by the dot notation in theaccompanying drawings. With the magnetically coupled inductors disclosedherein, inductively degenerated amplifier concepts can be extended byusing both self and mutual inductance.

In the LNAs discussed herein, several effects can occur at the sametime. Typically, metal oxide semiconductor (MOS) LNAs have a voltagegain from the input of the circuit to a gate of the amplifying device.This voltage gain can degrade the 3rd order intermodulation (IIP3)performance of the circuit. An attenuator is typically not used toreduce signal amplitude because such an attenuator can undesirablydegrade the noise performance of the circuit. The LNAs discussed hereincan include a negative feedback circuit. An amplifying device of an LNAcan receive a radio frequency (RF) signal by way of a first inductorthat is magnetically coupled to a degeneration inductor. The firstinductor can have a first end configured to receive the RF signal and asecond end electrically coupled to the amplifying device. The impedancelooking into a node at the first end of the first inductor (e.g., noden2 in FIGS. 41A to 41F) can be increased and the voltage at a node atthe second end of the first inductor (e.g., node n3 in FIGS. 41A to 41F)can be decreased. This may not reduce the gain, but the effect can allowthe circuit to be scaled differently, with a larger amplifying device.The higher input impedance can also allow the inductance of the inputmatch inductor that provides the RF signal to the first inductor to havea lower value. This can be advantageous when an on chip match inductoris implemented, as the Q of such devices can be limited, and theeffective series impedance of the input matching inductor can degradethe noise performance of the LNA. For instance, in one implementation,the input match inductor value is approximately half the value it wouldotherwise be without the magnetically coupled inductors. While thecircuits discussed herein may not give the absolutely best possiblenoise match, the magnetically coupled inductors can allow the inputmatch inductor to have a lower inductance and thereby recover at leastsome of the noise performance. The negative feedback provided bymagnetically coupled inductors discussed herein can provide an amplifierwith increased linearity.

One aspect of this disclosure is an impedance transformation circuit foruse in an amplifier, such as a low noise amplifier. The impedancetransformation circuit includes a matching circuit including a firstinductor. The impedance transformation circuit also includes a secondinductor. The first and second inductors are magnetically coupled toeach other to provide negative feedback to linearize the amplifier.

The second inductor can be a degeneration inductor, such as a sourcedegeneration inductor or an emitter degeneration inductor. The firstinductor can provide a radio frequency signal to an amplificationcircuit of the amplifier. The first inductor, the second inductor, andthe amplification circuit of amplifier can be embodied on a single die.

The matching circuit can further include a series inductor having afirst end and a second end, in which the first end is configured toreceive a radio frequency signal and the second end is electricallycoupled to the first inductor. The matching circuit can further includea shunt capacitor electrically coupled to the first end of the seriesinductor and/or a direct current (DC) blocking capacitor configured toprovide the radio frequency signal to the series inductor.

Another aspect of this disclosure is a low noise amplifier (LNA). TheLNA includes a matching circuit including a first inductor, anamplification circuit configured to receive a radio frequency signal byway of the first inductor and to amplify the radio frequency signal, anda second inductor. The first and second inductors are magneticallycoupled to each other to provide negative feedback to linearize the LNA.

The amplification circuit can include a common source amplifier or acommon emitter amplifier. A cascode transistor can be arranged in serieswith either of these amplifiers. Such a cascode transistor can be acommon drain amplifier or a common base amplifier. The second inductorcan be a source degeneration inductor or an emitter degenerationinductor.

The first inductor, the second inductor, and the amplification circuitof amplifier are can be embodied on a single die. The matching circuitcan further include a series inductor having a first end and a secondend, in which the first end is configured to receive the radio frequencysignal and the second end is electrically coupled to the first inductor.The matching circuit can further include a shunt capacitor electricallycoupled to the first end of the series inductor and/or a direct current(DC) blocking capacitor configured to provide the radio frequency signalto the series inductor.

Another aspect of this disclosure is a front end system that includes alow noise amplifier, a bypass path, and a multi-throw switch. The lownoise amplifier includes a matching circuit including a first inductor,an amplification circuit configured to receive a radio frequency signalby way of the first inductor and to amplify the radio frequency signal,and a second inductor magnetically coupled with the first inductor toprovide negative feedback to linearize the amplification circuit. Themulti-throw switch has at least a first throw electrically connected tothe low noise amplifier and a second throw electrically connected to thebypass path.

The front end system can further include a power amplifier, such as anyof the power amplifiers discussed herein. The multi-throw switch canhave a third throw electrically coupled to the power amplifier. The lownoise amplifier, the bypass path, the multi-throw switch, and the poweramplifier can be embodied on a single die.

The front end system can further include a second multi-throw switchhaving at least a first throw electrically connected to the low noiseamplifier and a second throw electrically connected to the bypass path,in which the low noise amplifier is included in a first signal pathbetween the multi-throw switch and the second multi-throw switch, and inwhich the bypass path is included in a second signal path between themulti-throw switch and the second multi-throw switch.

The multi-throw switch can electrically connect an input of the lownoise amplifier to an antenna in a first state, and the multi-throwswitch can electrically connect the bypass path to the antenna in asecond state. The front end system can further include the antenna. Theantenna can be integrated with the low noise amplifier, the bypass path,and the multi-throw switch.

The low noise amplifier, the multi-throw switch, and the bypass path canbe embodied on a single die. The front end system can include a packageenclosing the low noise amplifier, the multi-throw switch, and thebypass path.

In the front end system, the LNA can include any suitable combination offeatures of the LNAs and/or amplifiers discussed herein.

FIGS. 40A to 40D illustrate example low noise amplifier that includeimpedance transformation circuits with magnetically coupled inductorsarranged to linearize the low noise amplifiers. Any of these low noiseamplifiers can be implemented in a receive path in an RF system. The lownoise amplifiers can be implemented by any suitable process technology,such as silicon-on-insulator process technology. Any combination offeatures of the low noise amplifiers of FIGS. 40A to 40D can beimplemented as suitable.

FIG. 40A is a schematic diagram of a low noise amplifier (LNA) 1010 thatincludes an impedance transformation circuit according to an embodiment.As illustrated, the LNA 1010 includes an impedance transformationcircuit and an amplification circuit. The illustrated impedancetransformation circuit includes a first inductor 1012 and a secondinductor 1014. The illustrated amplification circuit includes fieldeffect transistors 1016 and 1018.

The second inductor 1014 illustrated in FIG. 40A is a sourcedegeneration inductor that can provide self-inductive degeneration. Thefirst inductor 1012 and the second inductor 1014 can together providemutual inductance effects that can improve linearity of the LNA 1010.The first inductor 1012 and the second inductor 1014 can togetherfunction as a transformer, with a primary winding in series with a gateof the field effect transistor 1016 and a secondary winding electricallyconnected at the source of the field effect transistor 1016. Asillustrated, the first inductor 1012 is magnetically coupled with thesecond inductor 1014. Accordingly, these inductors can provide negativefeedback to linearize the LNA 1010. The dot notation in FIG. 40Aindicates the phase of magnetic coupling between the first inductor 1012and the second inductor 1014.

The amplification circuit illustrated in FIG. 40A includes a commonsource amplifier 1016 and a common gate amplifier 1018. An RF inputsignal RF_IN can be provided to the gate of the common source amplifier1016 by way of the first inductor 1012. As illustrated, the common gateamplifier 1018 is arranged in series with the common source amplifier1016. Accordingly, the common gate amplifier 1018 can be referred to asa cascode transistor or a cascode field effect transistor. A biascircuit can provide a bias signal BIAS to the gate of the common gateamplifier 1018. The common gate amplifier 1018 can provide an RF outputsignal RF_OUT.

FIG. 40B is a schematic diagram of a low noise amplifier 1010′ thatincludes an impedance transformation circuit according to an embodiment.The low noise amplifier 10′ of FIG. 40B is similar to the low noiseamplifier 1010 of FIG. 40A, except that the amplification circuit inFIG. 40B is implemented by bipolar transistors instead of field effecttransistors. As illustrated in FIG. 40B, the amplification circuitincludes bipolar transistors 1022 and 1024. The amplification circuit ofFIG. 40B includes a common emitter amplifier 1022 in series with acommon base amplifier 1024. The second inductor 1014 of FIG. 40B is anemitter degeneration inductor.

FIG. 40C is a schematic diagram of a low noise amplifier 1010″ thatincludes an impedance transformation circuit according to an embodiment.An amplification circuit of an LNA can include a bipolar transistor anda field effect transistor. The bipolar transistor and the field effecttransistor of such an LNA can be arranged in a stack. FIG. 40Cillustrates an example of an LNA 1010″ that includes a bipolartransistor and a field effect transistor arranged in a stack. Asillustrated in FIG. 40C, the LNA 1010″ includes a bipolar transistor1022 arranged as a common emitter amplifier and a cascode filed effecttransistor 1018 arranged as a common gate amplifier. Alternatively, alow noise amplifier can include a common source amplifier and a commonbase amplifier arranged in a stack.

FIG. 40D is a schematic diagram of a low noise amplifier 1010′″ thatincludes an impedance transformation circuit according to an embodiment.The amplification circuits shown in FIGS. 40A to 40C are exampleamplification circuits that can be implemented in connection with animpedance transformation circuit that includes magnetically coupledinductors that provide negative feedback to linearize an LNA. FIG. 40Dshows that the first inductor 1012 and the second inductor 1014 can beimplemented in connection with any suitable amplification circuit, asshown by amplification circuit 1026. The amplification circuit 1026 canbe implemented by the amplification circuit of FIG. 40A, theamplification circuit of FIG. 40B, the amplification circuit of FIG.40C, or any other suitable amplification circuit.

FIGS. 41A, 41B, and 41C are schematic diagrams of low noise amplifiersystems that include low noise amplifiers according to certainembodiments. These LNAs include different input matching circuits. Anyof the principles and advantages of these matching circuits can beimplemented in connection with any of the amplifiers discussed herein asappropriate.

FIG. 41A is a schematic diagram of a low noise amplifier system 1030that includes an LNA and a bias circuit 1032. The LNA illustrated inFIG. 41A includes a matching circuit, an amplification circuit, and adegeneration inductor. The amplification circuit of this LNA correspondsto the amplification circuit of the LNA 1010 of FIG. 40A. It will beunderstood that any of the principles and advantages discussed withreference to FIGS. 41A to 41C can be implemented in connection withother suitable amplification circuits, such as the amplification circuitof the LNA 1010′ of FIG. 40B and/or the amplification circuit 1026 ofthe LNA 10″ of FIG. 40C. In FIG. 41B, the inductors 1012 and 1104 aremagnetically coupled to each other and can function as discussed above.

The matching circuit illustrated in FIG. 41A includes the first inductor1012, a series inductor 1036, and a shunt capacitor 1038. The matchingcircuit can provide input impedance matching for the LNA. The RF inputsignal RF_IN can be provided at node n1. The shunt capacitor 1038 iselectrically connected to the series inductor 1036 at node n1. The shuntcapacitor 1038 can provide impedance matching at node n1. For instance,the impedance of the shunt capacitor 1038 can terminate at a phasecorresponding to a fundamental frequency of the RF input signal RF_IN.The RF input signal RF_IN can be provided to the amplification circuitof the LNA by way of the series inductor 1036 and the first inductor1012. Magnetic coupling between the first inductor 1012 and the secondinductor 1014 can increase the impedance at node n2. Accordingly, theimpedance at node n1 can be increased by this magnetic coupling. Thus,with the increase in impedance from this magnetic coupling, theinductance of the first inductor 1012 and/or the inductance of theseries inductor 1036 can be decreased and provide similar inputmatching. This can advantageously decrease the physical area of thefirst inductor 1012 and/or the series inductor 1036, which can besignificant. Inductors with relatively lower inductance can also improvenoise performance of the LNA.

The bias circuit 1032 can provide a first bias for the common sourceamplifier 1016 at node n2. The first bias can be provided to the gate ofthe common source amplifier 1016 by way of the first inductor 1012. Insome instances, the bias circuit 32 can provide a second bias to thegate of the common gate amplifier 1018. The bias circuit 1032 can beimplemented by any suitable bias circuit.

The low noise amplifier system 1030′ of FIG. 41B is similar to the lownoise amplifier system 1030 of FIG. 41A, except that the matchingcircuit of the LNA in FIG. 41B also includes a DC blocking capacitor1039. As illustrated, the DC blocking capacitor 1039 is coupled betweena received RF signal and node n1. The DC blocking capacitor 1039 canblock DC signal components of the RF input signal RF_IN from beingprovided to node n1.

The low noise amplifier system 1030″ of FIG. 41C is similar to the lownoise amplifier system 1030′ of FIG. 41B, except that the matchingcircuit of the LNA in FIG. 41C does not include the shunt capacitor1038.

FIG. 41D is schematic diagram of low noise amplifier system 1030′″ thatincludes an example bias circuit according to an embodiment. The biascircuit of FIG. 41D is an example of the bias circuit 1032 of FIGS. 41Ato 2C. The bias circuit can include a current mirror to provide a biassignal to an amplification circuit of an LNA. As illustrated in FIG.41D, the bias circuit includes transistors 1061 and 1062, and a biasingelement 1063, such as a resistor. The bias circuit is configured toprovide a bias voltage to the transistor 1016 by way of the biasingelement 1063. The biasing input signal BIAS_IN can be a current providedby a current source.

FIG. 41E is schematic diagram of low noise amplifier system 1030′″ thatincludes a bias and matching circuit 1064 coupled to an output of a lownoise amplifier according to an embodiment. The bias and matchingcircuit 1064 can include any suitable circuit elements to bias theoutput of the LNA and/or to provide impedance matching at the output ofthe LNA. The bias and matching circuit 1064 can be implemented inconnection with any of the LNAs discussed herein.

FIG. 41F is schematic diagram of low noise amplifier system 1030″″ thatincludes an example bias and matching circuit coupled to an output of alow noise amplifier according to an embodiment. The bias and matchingcircuit of FIG. 41F is an example of the bias and matching circuit 1064of FIG. 41E. The bias and matching circuit of FIG. 41F includes aninductor 1065 and a capacitor 1067. The inductor 1065 can provide a biasto the output of the LNA. The capacitor 1067 can provide impedancematching. Other suitable passive impedance networks can alternatively beimplemented to provide biasing and impedance matching at the output ofthe LNA.

FIG. 42 is a Smith chart corresponding to the matching circuit and thedegeneration inductor of the low noise amplifier system of FIG. 41A.This Smith chart shows how the input impedance from the startingimpedance varies when the magnetically coupled inductors 1012 and 1014are implemented. The arrow on this chart shows the direction forincreasing magnetic coupling. Locus A shows how the impedance at node n2of FIG. 41A varies as the coupling factor is changed between the firstinductor 1012 and the second inductor 1014. Locus A is relatively closeto the effect of adding a series resistance. Locus B is the addition ofthe series inductor 1036, from the point where locus A crosses the 50Ohm resistance line. The net effect is that the series inductor 1036 canalso be significantly smaller (e.g., in the example shown B=1 nH andC=2.7 nH at 2.5 GHz). Locus C shows the effect of the series inductor1036. Locus D shows the effect of the shunt capacitor 1038.

Some or all of the circuit elements of the LNAs and/or front end systemsdiscussed above can be implemented on a single semiconductor die. FIG.43 illustrates a physical layout of magnetically coupled inductors of alow noise amplifier according to an embodiment. As illustrated, a die1049 includes an amplification circuit 1026, a first inductor 1012, anda second inductor 1014 that is magnetically coupled with the firstinductor 1012. The die 1049 can also include a series inductor 1036, asillustrated. The die 1049 can be manufactured using any suitable processtechnology. As one example, the die 1049 can be asemiconductor-on-insulator die, such as a silicon-on-insulator die.

The first inductor 1012 and the second inductor 1014 can each includeone or more annular turns. The first inductor 1012 and the secondinductor 1014 can be interleaved with each other. In some instances, thefirst inductor 1012 and/or the second inductor 1014 can be implementedin two metal layers with conductive connections between metals in thetwo metal layers. This can lower resistance of the metal and increasethe quality factor of an inductor.

The first inductor 1012 and the second inductor can be wound around amagnetic core in some instances. Alternatively, a magnetic core can beimplemented around the first inductor 1012 and the second inductor 1014in certain applications.

While FIG. 43 is not necessarily to scale, this drawing illustrates thatthe first inductor 1012 and the second inductor 1014 can be relativelylarge and can consume significant physical die area. As alsoillustrated, the series inductor 1036 can be relatively large and canconsume significant physical die area. Accordingly, reducing theinductance and thus the size of the first inductor 1012 (and/or theseries inductor 1036 described above) can result in a significantreduction in physical area consumed by an LNA.

The low noise amplifiers discussed herein, which can be as describedearlier in this section, can be included in any suitable front endsystem, packaged module, semiconductor die (e.g., asemiconductor-on-insulator die, such as a silicon-on-insulator die),wireless communication device (e.g., a mobile phone, such as a smartphone), or the like.

Section II—Overload Protection of Low Noise Amplifier

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to overload protection of low noiseamplifiers (LNAs). In certain configurations, an LNA system includes aninput switch having an analog control input that controls an impedanceof the input switch, an LNA that amplifies a radio frequency (RF) inputsignal received from the input switch, and an overload protectioncircuit that provides feedback to the input switch's analog controlinput based on detecting a signal level of the LNA. The overloadprotection circuit detects whether or not the LNA is overloaded.Additionally, when the overload protection circuit detects an overloadcondition, the overload protection circuit provides feedback to theanalog control input of the switch to increase the impedance of theswitch and reduce the magnitude of the RF input signal received by theLNA. As indicated above, aspects of this section may be combined withother aspects of one or more other sections to further improve theperformance of front end systems and related devices, integratedcircuits, modules, and methods in which they are employed.

Large input signals can cause overload conditions to arise in a lownoise amplifier (LNA). For example, in certain applications, an LNA isspecified to tolerate a high overload signal that is substantiallyhigher than a normal operating signal level.

Absent an overload protection scheme, providing a large input signal toan LNA can result in high current and/or voltage manifesting incircuitry of the LNA, such as transistors used for amplification. Suchhigh current and/or voltage can cause permanent electrical overstressdamage to the amplification transistors such that they are no longerable to operate and/or such that their operation is impaired.

Apparatus and methods for overload protection of LNAs are providedherein. In certain configurations, an LNA system includes an inputswitch having an analog control input that controls an impedance of theinput switch, an LNA that amplifies a radio frequency (RF) input signalreceived from the input switch, and an overload protection circuit thatprovides feedback to the input switch's analog control input based ondetecting a signal level of the LNA. The overload protection circuitdetects whether or not the LNA is overloaded. Additionally, when theoverload protection circuit detects an overload condition, the overloadprotection circuit provides feedback to the analog control input of theswitch to increase the impedance of the switch and reduce the magnitudeof the RF input signal received by the LNA.

The overload protection schemes herein can be used to limit largecurrent and/or voltage swing conditions manifesting within circuitry ofan LNA.

In certain implementations, the input switch is also used forcontrolling signal connectivity and/or routing. For example, the inputswitch can be part of a multi-throw switch used to facilitate routing ofsignals transmitted and received via an antenna. Using the input switchfor both overload protection and signal routing can reduce overheadand/or enhance performance by sharing circuitry for multiple functions.For example, using an input switch that is already in a receive signalpath provides overload protection without increasing the insertion lossof the receive path. Thus, the overload protection circuit has no or arelatively small impact on the LNA's performance.

The teachings herein can be used to control the impedance of an inputswitch to attenuate an incoming RF signal to a safe level. For an inputswitch, such as a metal-oxide-semiconductor (MOS) transistor switch, ananalog control input can be used to control the input switch'simpedance. For example, the impedance of a MOS transistor switch can becontrolled based on an analog voltage level provided to the MOStransistor's gate.

In certain implementations herein, the overload protection circuitcontrols the analog control input of the input switch with an overloadprotection signal that is based on a detected signal level of the LNA,such as an input signal level, internal signal level, and/or outputsignal level. Additionally, the overload protection circuit providesfeedback to the input switch's analog control input via the overloadprotection signal to prevent a large input signal from damaging the LNA.

In certain configurations, the impedance of the input switch can becontrolled based not only on the overload protection signal from theoverload protection circuit, but also on one or more digital controlsignals. For example, in certain implementations, the overloadprotection circuit includes a limiter enable circuit connected betweenan output of the overload protection circuit and the analog controlinput to the input switch. The limiter enable circuit controls the inputswitch based on one or more digital control signals, such as a switchenable signal and/or limiter enable signal. For example, the limiterenable circuit can be used to disconnect the overload protection circuitfrom the analog control input when the input switch is in an off stateand/or when overload protection is disabled.

The signal level of the LNA can be detected in a wide variety of ways,such as by using any suitable signal detector. For example, a signaldetector can be used to detect an input signal level of the LNA, aninternal signal level of the LNA, and/or an output signal level of theLNA. For instance, detection at the LNA's output avoids noise figuredegradation, but can degrade the LNA's linearity. In contrast, detectionat the LNA's input may degrade noise figure. Detection at the outputalso relaxes design constraints of the detector, since the output signallevel is higher than the input signal level.

In certain implementations, the LNA includes an output rectifier circuitthat clips or limits an output voltage level of the LNA. Including theoutput rectifier circuit can enhance performance, since the outputrectifier circuit can have a faster turn-on time relative to a timetaken by feedback from the overload protection circuit to increase theimpedance of the input switch. In one example, the output rectifier isimplemented using clamping diodes. Once the overload protectioncircuit's control loop responds to provide feedback, the signal level isturned down or decreased to a safe level via control of the impedance ofthe input switch.

A network or circuit connected in shunt with a signal path can impactoverall noise or linearity performance. By providing overload protectionusing an input switch already present, the LNA need not include anadditional circuit in shunt or series to protect against overload.

The overload protection circuits herein can provide signal attenuationat the LNA's input via increasing impedance of the input switch.Accordingly, the overload protection schemes herein can be used toprotect against both high voltage and high current. Furthermore,reducing the RF input signal to the LNA protects all circuitry of theLNA. In contrast, an implementation using only an output voltage clampmay not fully protect certain circuits of the LNA and/or high currentsmay nevertheless flow in the LNA when clamping.

The LNA overload protection schemes disclosed herein are applicable to awide variety of RF systems, including, but not limited to, smartphones,base stations, handsets, wearable electronics, and/or tablets.

FIG. 44 is a schematic diagram of an LNA system 1110 according to oneembodiment. The LNA system 1110 includes an input switch 1101, an LNA1102, and an overload protection circuit or signal limiter 1103. The LNAsystem 1110 further includes an input terminal 1107 and an outputterminal 1108.

The LNA 1102 provides amplification to an RF input signal received fromthe input terminal 1107 via the input switch 1101. The LNA 1102 providesan amplified RF output signal on the output terminal 1108. In certainconfigurations, the input terminal 1107 is electrically connected to anantenna and the output terminal 1108 is electrically connected to atransceiver. For instance, the transceiver can include a demodulatorthat downconverts the amplified RF output signal from the LNA 1102 tobaseband or an intermediate frequency.

The input switch 1101 includes an analog control input used to controlthe input switch's impedance between the input terminal 1107 and aninput to the LNA 1102. In certain configurations, the input switch 1101includes at least one metal-oxide-semiconductor (MOS) transistor havinga gate that serves as the analog control input. By controlling an analoggate voltage of the MOS transistor, an impedance of the input switch canbe controlled.

As shown in FIG. 44, the overload protection circuit 1103 detects asignal level of the LNA 1102 to determine whether or not an overloadcondition is present. Additionally, the overload protection circuit 1103generates an overload protection signal OP operable to provide feedbackto the analog control input of the switch 1101. When the overloadprotection circuit 1103 detects an overload condition, the overloadprotection circuit 1103 increases the impedance of the input switch1101, thereby reducing the magnitude of the RF input signal received bythe LNA 1102. Thus, the overload protection circuit 1103 serves as asignal limiter that limits large current and voltage swing conditionsmanifesting within amplification transistors of the LNA 1102.

In certain implementations, the input switch 1101 corresponds to part ofa multi-throw switch used to facilitate routing of signals transmittedand received via an antenna. For example, the input terminal 1107 can beconnected to an antenna of a wireless device. Using the input switch1101 for both overload protection and routing signals can reduceoverhead and/or enhance performance. Thus, during normal signalingconditions when no overload condition is present, the overloadprotection circuit 1103 has no or a relatively small impact on theperformance of the LNA 1102. For instance, since the input switch 1101is included for signal routing, the overload protection scheme need notincrease an insertion loss between the input terminal 1107 and theoutput terminal 1108.

Although not illustrated in FIG. 44, the LNA system 1110 can includeother components and/or circuitry. For example, in one embodiment, theLNA system 1110 further includes a limiter enable circuit connectedbetween the output of the overload protection circuit 1103 and theanalog control input to the input switch 1101. In certainimplementations, the limiter enable circuit can be used to selectivelyconnect the output of the overload protection circuit 1103 and the inputswitch's analog control input based on a state of a switch enablesignal.

FIG. 45A is a schematic diagram of an LNA system 1115 according toanother embodiment. The LNA system 1115 of FIG. 45A includes the inputterminal 1107, the output terminal 1108, the input switch 1101, the LNA1102, and the overload protection circuit 1103, which can be asdescribed earlier. The LNA system 1115 further includes a limiter enablecircuit 1126.

The LNA system 1115 of FIG. 45A is similar to the LNA system 1110 ofFIG. 44, except that the LNA system 1115 further includes the limiterenable circuit 1126. As shown in FIG. 45A, the limiter enable circuit1126 receives a limiter enable signal LEN and a switch enable signalSWEN, in this embodiment. Although FIG. 45A illustrates one example ofdigital control signals for a limiter enable circuit, otherimplementations are possible.

The limiter enable circuit 1126 receives the overload protection signalOP from the overload protection circuit 1103. The limiter enable signalLEN can be used to selectively enable overload protection/signal limiterfunctionality based on a state of digital control signals received bythe limiter enable circuit 1126.

In the illustrated embodiment, when the switch enable signal SWEN andlimiter enable signal LEN are enabled, the limiter enable circuit 1126provides the overload protection signal OP to the analog control inputof the input switch 1101. However, when the switch enable signal SWEN isdisabled, the limiter enable circuit 1126 controls the analog controlinput to turn off the input switch 1101. Additionally, when the limiterenable signal LEN is disabled, the input switch 1101 can be turned on oroff based on the state of the switch enable signal SWEN.

Including the limiter enable circuit 1126 between the output of theoverload protection circuit 1103 and the analog control input of theinput switch 1101 provides a number of advantages. For example, thelimiter enable circuit 1126 allows the switch state to be controlled bya logic signal, while also allowing the overload protection circuit 1103to provide feedback to the input switch's analog control input whendesired.

For example, when the switch enable signal SWEN is in a disabled state,the limiter enable circuit 1126 disconnects the output of the overloadprotection circuit 1103 from the analog control input and turns off theinput switch 1101. However, when the switch enable signal SWEN and thelimiter enable signal LEN are in enabled states, the limiter enablecircuit 1126 connects the output of the overload protection circuit 1103to the analog control input of the input switch 1101.

FIG. 45B is a schematic diagram of an LNA system 1120 according toanother embodiment. The LNA system 1120 includes the input terminal1107, the output terminal 1108, the input switch 1101, the LNA 1102, andthe limiter enable circuit 1126, which can be as described earlier. TheLNA system 1120 further includes an overload protection circuit orsignal limiter 1123.

The illustrated overload protection circuit 1123 includes a detector1124 and an error amplifier 1125. The detector 1124 generates adetection signal DET based on detecting a signal level of the LNA 1102.The detector 1124 can sense the signal level of the LNA 1102 in avariety of ways, including, for example, output signal detection, inputsignal detection, and/or detection of an intermediate voltage and/orcurrent.

As shown in FIG. 45B, the error amplifier 1125 amplifies the detectionsignal DET to generate an overload protection signal OP, which isprovided to the limiter enable circuit 1126. In certain implementations,the error amplifier 1125 amplifies a difference between the detectionsignal DET and a reference signal.

Although FIG. 45B illustrates one embodiment of an overload protectioncircuit, the overload protection circuits herein can be implemented in awide variety of ways.

FIG. 46A is a schematic diagram of an LNA 1131 and a detector 1132according to one embodiment. The LNA 1131 includes an LNA input RFIN andan LNA output RFOUT. The detector 1132 includes a detector input coupledto an internal node of the LNA 1131 and a detector output DET.

The LNA 1131 further includes an amplification NPN transistor 1141, acascode n-type metal-oxide-semiconductor (NMOS) transistor 1142, anemitter degeneration inductor 1143, and a biasing inductor 1144.Although one implementation of an LNA is shown in FIG. 46A, theteachings herein are applicable to LNAs implemented in a wide variety ofways, including but not limited to, LNAs using more or fewer transistorsand/or transistors of different device types and/or polarities.

As shown in FIG. 46A, the base of the amplification NPN transistor 1141is connect to the LNA input RFIN, and the collector of the amplificationNPN transistor 1141 is connected to a source of the cascode NMOStransistor 1142. The emitter degeneration inductor 1143 is electricallyconnected between an emitter of the amplification NPN transistor 1141and a first voltage V1 (for instance, ground), and the biasing inductor1144 is electrically connected between a drain of the cascode NMOStransistor 1142 and a second voltage V2 (for instance, a power supply).The gate of the cascode NMOS transistor 1142 is biased by a bias voltageVBIAS and the drain of the cascode NMOS transistor 1142 is connected tothe LNA output RFOUT. For clarity of the figures, bias circuitry of theLNA 1131 has not been shown. However, the LNA 1131 can be biased in awide variety of ways.

The illustrated detector 1132 includes a first detection NPN transistor1151, a second detection NPN transistor 1152, a detection p-typemetal-oxide-semiconductor (PMOS) transistor 1153, a Schottky diode 1159,a first resistor 1161, a second resistor 1162, a third resistor 1163, afirst capacitor 1165, and a second capacitor 1166. Although oneimplementation of a detector is shown in FIG. 46A, the teachings hereinare applicable to detectors implemented in a wide variety of ways.

In the illustrated embodiment, the detector 1132 generates a detectioncurrent IDET at the detector output DET. The magnitude of the detectioncurrent IDET is based on a detected signal level of the LNA 1131, and inparticular to a signal swing at the collector of the amplification NPNtransistor 1141. However, a signal detector can detect an LNA's signallevel in other ways. Moreover, although the illustrated detector 1132generates a detection current, other configurations are possible,including but not limited to, implementations in which a detectorgenerates a detection voltage.

At high signal power the voltage at the collector of the amplificationNPN transistor 1141 saturates the first detection NPN transistor 1151,which gives rise to a flow of rectified current through the firstdetection NPN transistor 1151. The rectified current is filtered by thefirst capacitor 1165 to generate a voltage the controls a gate of thedetection PMOS transistor 1153. Thus, when the LNA 1131 is in overload,a detection current IDET flows from the detector 1132.

The illustrated embodiment depicts one implementation of an LNA anddetector suitable for use in an LNA system, such as the LNA system 1120of FIG. 45B. Although FIG. 46A illustrates one embodiment of an LNA anddetector, the teachings herein are applicable to LNAs and detectorsimplemented in a wide variety of ways.

FIG. 46B is a schematic diagram of an LNA 1191 and a detector 1132according to another embodiment. The schematic diagram of FIG. 46B issimilar to the schematic diagram of FIG. 46A, except that the LNA 1191of FIG. 46B further includes an output rectifier circuit 1192electrically connected to the LNA output RFOUT.

In certain implementations, such as the embodiment of FIG. 46B, an LNAis protected not only using an overload protection circuit that providesfeedback to an input switch, but also using an output rectifier circuitthat clips or limits an output voltage level of the LNA. Including theoutput rectifier circuit can enhance performance, since the outputrectifier circuit can have a faster turn-on time relative to a timetaken by feedback from the overload protection circuit to increase theimpedance of the input switch. Once the overload protection circuit'scontrol loop responds to provide feedback, the signal level is turneddown or decreased to a safe level via control of the impedance of theinput switch.

In one embodiment, the output rectifier circuit 1192 is implementedusing clamping diodes. For example, the output rectifier can include oneor more diode networks electrically connected between the LNA outputRFOUT and one or more reference voltages, for instance, between the LNAoutput RFOUT and the first voltage V1 and/or between the LNA outputRFOUT and the second voltage V2.

FIG. 47 is a schematic diagram of an error amplifier 1200 according toone embodiment. The error amplifier 1200 includes a first NMOStransistor 1201, a second NMOS transistor 1202, a third NMOS transistor1203, a fourth NMOS transistor 1204, a fifth NMOS transistor 1205, asixth NMOS transistor 1206, a first PMOS transistor 1211, a second PMOStransistor 1212, a first resistor 1221, a second resistor 1222, a thirdresistor 1223, and a reference current source 1225. The error amplifier1200 includes a detection input DET for receiving a detection signalfrom a detector. The error amplifier 1200 further includes an overloadprotection output OP, which can be used to control an analog controlinput of an input switch.

In the illustrated embodiment, a detection current IDET from a detector(for example, the detector 1132 of FIGS. 46A-46B) is received by theerror amplifier 1200. When the detection current IDET is greater thanthe reference current IREF of the reference current source 1225, thesecond NMOS transistor 1202 can turn off and the first NMOS transistor1201 can conduct. Since the first and third NMOS transistors 1201, 1203operate as a first current mirror and the first and second PMOStransistors 1211, 1212 operate as a second current mirror, the overloadprotection output OP is pulled down when the detection current IDET isgreater than the reference current IREF.

The first resistor 1221 aids in preventing the first and second NMOStransistors 1201, 1202 from simultaneously conducting. For example, thefirst resistor 1221 operates in conjunction with the fourth and fifthNMOS transistors 1204, 1205 to bias the first and second NMOStransistors 1201, 1202 near conduction, while inhibiting simultaneouslyconduction. This in turn prevents a continuously linear closed loop whenthe error amplifier 1200 is connected in a feedback loop from an LNA toan analog control input of an input switch. As shown in FIG. 47, a biascurrent IBIAS is used to bias the first resistor 1221 and the fourth andfifth NMOS transistors 1204, 1205.

At very high input power to an LNA, a detector can generate a relativelylarge detection signal, which can result in the overload protectionoutput OP being controlled to the first voltage VI. At intermediateinput power levels, the circuit can exhibit blocking oscillatorbehavior. In certain implementations, there is no continuous linearsignal path around the loop, but instead a switched oscillatorybehavior.

In certain implementations, the feedback signal generated at theoverload protection output OP can be provided to a limiter enablecircuit (for example, the limiter enable circuit 1126 of FIGS. 45A-45B),which in turn can selectively provide the feedback signal to an analogcontrol input of an input switch. When a large input signal is presentduring an overload condition, the overload protection output OP goes low(in this embodiment), which in can turn off the input switch eitherfully or partially.

For example, the input switch includes an analog control input, and thusthe magnitude of the input signal to an LNA can be controlled using theoverload protection output OP. Since turning off the input switchpartially reduces the input signal strength to the LNA and acorresponding value of the detector signal DET, a closed loop isprovided. The closed loop exhibits different behavior at different inputpower levels. At very high power, the input switch is fully off andsubstantially no input signal is provided to the LNA. At intermediatepower levels, when the loop exhibits some oscillatory behavior, theoverload protection output OP can operate at a DC level with asuperimposed AC component. In certain implementations, the input switchfilters the AC component, since the input switch can be implemented tohave a time constant lower than the period of the oscillatory signal.Accordingly, the loop can behave as though it were under linear control.

In certain configurations, the loop does not respond to any signallevels encountered in normal operation, only to higher overloadconditions. The protection loop has a finite response time, and thus maynot protect against instantaneous voltage peaks. However, the protectionloop can limit total exposure of the LNA to high currents. In certainconfigurations, an LNA further includes an output rectifier to bolsterprotection against instantaneous voltage peaks.

In the illustrated embodiment, the overload protection output OP isnormally high. However, when an overload condition is detected, theoverload protection output OP is a continuously variable level, that canvary between the voltages of the first voltage V1 and the second voltageV2. The analog or continuous signal level of the overload protectionoutput OP arises from the error amplifier 1200 operating in a closedloop. The overload protection output OP is controlled to a voltage levelthat depends on an input power to the LNA and operating conditions, suchas temperature.

The illustrated embodiment depicts one implementation of an erroramplifier for use in an LNA system, such as the LNA system 1120 of FIG.45B. Although one embodiment of an error amplifier is shown in FIG. 47,an error amplifier can be implemented in other ways.

FIG. 48A is a schematic diagram of a limiter enable circuit 1240according to one embodiment. The limiter enable circuit 1240 includes adigital control circuit 1241 and a feedback enable circuit 1242. Thelimiter enable circuit 1240 receives an overload protection signal OPand one or more digital control signals, and generates a switch controlsignal SWCTL used to control an analog control input of an input switch,such as the input switch 1101 of FIG. 44.

As shown in FIG. 48A, the digital control circuit 1241 receives one ormore digital control signals, which the digital control circuit 1241processes to control whether or not the feedback enable circuit 1242 isturned on or off. When the feedback enable circuit 1242 is turned on,the overload protection signal OP is used to control an analog voltagelevel of the switch control signal SWCTL. However, when feedback enablecircuit 1242 is turned off, the digital control circuit 1241 digitallycontrols the switch control signal SWCTL.

FIG. 48B is a schematic diagram of a limiter enable circuit 1251according to another embodiment. The limiter enable circuit 1251includes a digital control circuit 1271 that includes a first inverter1291, a second inverter 1292, a third inverter 1293, a first NAND gate1295, a second NAND gate 1296, a first PMOS transistor 1281, and a firstNMOS transistor 1283. The limiter enable circuit 1251 further includes afeedback enable circuit 1272 that includes a second PMOS transistor 1282and a second NMOS transistor 1284.

In the illustrated embodiment, the digital control circuit 1271 receivesa limiter enable signal LEN and a switch enable signal SWEN. The digitalcontrol circuit 1271 controls whether or not the feedback enable circuit1272 is enabled based on a state of the limiter enable signal LEN andthe switch enable signal SWEN, in this embodiment.

For example, in the illustrated embodiment, when the limiter enablesignal LEN is logically low (corresponding to disabled, in thisembodiment), the digital control circuit 1271 turns off the feedbackenable circuit 1272 and digitally controls the switch control signalSWCTL to have the same state as the switch enable signal SWEN.Additionally, when the limiter enable signal LEN is logically low andthe switch enable signal SWEN is logically low, the digital controlcircuit 1271 shuts off the feedback enable circuit 1272 and digitallycontrols the switch control signal SWCTL logically low, in thisembodiment. However, when the limiter enable signal LEN and the switchenable signal SWEN are logically high, the digital control circuit 1271turns off the feedback enable circuit 1272 and the overload protectionsignal OP controls the switch enable signal SWCTL.

Although FIG. 48B illustrates one embodiment of a limiter controlcircuit in accordance with the teachings herein, limiter controlcircuits can be implemented in a wide variety of ways. Moreover, theteachings herein are applicable to implementations in which a limitercontrol circuit is omitted.

FIG. 49 is a schematic diagram of an LNA system 1250 according toanother embodiment. The LNA system 1250 includes the input terminal1107, the output terminal 1108, the LNA 1102, the overload protectioncircuit 1103, and the limiter enable circuit 1251, which can be asdescribed earlier. The LNA system 1250 further includes an input switch1252.

The illustrated input switch 1252 includes a first NMOS transistor 1261and a second NMOS transistor 1262 electrically connected in series withone another. In the illustrated embodiment, the gates of the NMOStransistors 1261, 1262 serve as the analog control input to the inputswitch 1252. Additionally, the RF input signals passes from the inputterminal 1107 to the input of the LNA 1102 via the channels of the NMOStransistors 1261, 1262. Although one implementation of an input switchis shown, an input switch can be implemented in other ways.

As shown in FIG. 49, the limiter enable circuit 1251 is connectedbetween an output of the overload protection circuit or limiter 1103 andthe analog control input to the input switch 1252. The logic of thelimiter enable circuit 1251 is implemented to disconnect the overloadprotection circuit 1103 from the analog control input when the switchenable signal SWEN and/or limiter enable signal LEN is disabled.

Thus, the overload protection circuit 1103 controls the analog controlinput of the input switch 1252 when the switch enable signal SWEN andlimiter enable signal LEN are enabled. However, when the switch enablesignal SWEN is disabled, the limiter enable circuit 1251 can control theanalog control input to the first voltage V1 (for instance, ground or anegative voltage), to turn off the input switch 1252. Additionally, thelimiter enable signal LEN is used to disable overload protection/signallimiter functionality. Thus, when the limiter enable signal LEN isdisabled, the input switch 1252 can be turned on or off based on thestate of the switch enable signal SWEN.

The switch enable signal SWEN and limiter enable LEN can be generated ina variety of ways. In certain configurations, an integrated circuit (IC)includes one or more registers used to control a state of the switchenable signal SWEN and/or limiter enable LEN. For example, the one ormore registers can be programmed by a transceiver over an interface,such as a serial peripheral interface. However, the switch enable signalSWEN and/or limiter enable signal LEN can be generated in other ways,such as being provided via pins of the IC.

Additional details of the LNA system 1250 can be as described herein.

An input switch 1101, an LNA 1102, and an overload protection circuit1103, which can be as described earlier in this section, can be includedin any suitable front end system, packaged module, semiconductor die(e.g., a semiconductor-on-insulator die, such as a silicon-on-insulatordie), wireless communication device (e.g., a mobile phone, such as asmart phone), or the like.

Section III—Multi-Mode Power Amplifier

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to a multi-mode power amplifier. Amulti-mode power amplifier circuit includes a stacked amplifier and abias circuit. The stacked amplifier includes at least a first transistorand a second transistor in series with each other. The stacked amplifieris operable in at least a first mode and a second mode. The bias circuitis configured to bias the second transistor to a linear region ofoperation in the first mode and to bias the second transistor as aswitch in the second mode. In certain embodiments, the stacked amplifiercan be a power amplifier stage configured to receive a supply voltagethat has a different voltage level in the first mode than in the secondmode. As indicated above, aspects of this section may be combined withother aspects of one or more other sections to further improve theperformance of front end systems and related devices, integratedcircuits, modules, and methods in which they are employed.

It can be desirable to manage the amplification of an RF signal, asamplifying the RF signal to an incorrect power level or introducingsignificant distortion to the original RF signal can cause a wirelesscommunication device to transmit out of band and/or violate compliancewith an accepted standard. Biasing a power amplifier device can be asignificant part of managing the amplification because it can determinethe voltage and/or current operating point of the amplifying deviceswithin the power amplifier.

Certain power amplifier circuits include stacked power amplifiertopologies. For instance, device stacking for silicon-on-insulator poweramplifier circuit topologies can overcome relatively low breakdownvoltages of scaled transistors. Such device stacking can be beneficialin applications in which a stacked amplifier is exposed to a relativelylarge voltage swing, such as a voltage swing exceeding about 2.75 Volts.Stacking several transistors, such as 3 or 4 transistors, can result ina power amplifier with desirable operating characteristics. Forinstance, a power amplifier with such stacked transistors can behavedesirably for supply voltages in a range between about 3 Volts to about3.6 Volts and voltage swings approaching about 8 Volts withoutexperiencing significant hot carrier injection (HCl) and correspondinglong-term effects of reduced transistor drain current and increasedtransistor leakage.

Multi-mode power amplifiers can include a supply control circuit thatprovides the power amplifier with a power supply voltage that can varydepending on a mode of operation of the power amplifier. As an example,in a multiple power-mode, variable supply power amplifier, a lowersupply voltage can be provided in a lower power mode and a higher supplyvoltage can be provided in a higher power mode. In some instances, apower amplifier can include multiple stages and the supply voltageprovided to the stacked output stage can be varied depending on thepower mode while a different supply voltage for an earlier stage remainssubstantially constant. When a supply voltage for a power amplifier isreduced in a lower power mode for efficiency purposes, the supplyvoltage can be significantly lower than for a higher power mode. Forexample, the supply voltage for a lower power mode can be about 60%below the supply voltage for a higher mode. Such a reduction in supplyvoltage can result in reduced drain-to-source voltage (VDS) headroomoperation that drives stacked-device field effect transistor (FET)topologies into early power compression, which can in turn reduce theattainable output 1 dB compression point (OP1 dB), saturated power(PSAT), and/or power-added efficiency (PAE) of the power amplifier.

Aspects of this section relate to a stacked amplifier and bias circuit.The stacked amplifier includes at least a first transistor and a secondtransistor in series with each other. The stacked amplifier is operablein at least a first mode and a second mode. The bias circuit isconfigured to bias the second transistor to a linear region of operationin the first mode. The bias circuit is configured to bias the secondtransistor as a switch in the second mode. Accordingly, the bias circuitcan bias the stacked amplifier such that the stacked amplifier behaveslike there is at least one less transistor in the stack in the secondmode relative to the first mode. Such operation can result in meetingdesign specifications for different power modes, in which a supplyvoltage provided to the stacked amplifier is lower in the second modethan in the first mode.

For example, in a stacked silicon-on-insulator power amplifier, anoutput stage can include a stacked architecture with a common sourcetransistor in series with one or more common gate transistors. This canprevent breakdown during high and/or medium power modes of operation(e.g., modes in which a supply voltage for the output stage are 3 Voltsand 1.8 Volts, respectively). In the lowest power mode of operation(e.g., a mode with a supply voltage for the output stage of 1.2 Volts),both the specified power supply level and the voltage swing can bebetter accommodated by having at least one less transistor in the stack.In certain implementations, a common gate transistor in the stackedamplifier being operated as a switch (as opposed to a common gate stage)by turning it ON hard enough such that its VDS is sufficiently low(e.g., less than about 100 mV or less than about 75 mV) to therebyreduce and/or minimize its effect on the headroom and allowing improvedOP1 dB and PSAT (e.g., about 13 dBm).

Accordingly, certain embodiments discussed herein can overcome problemsassociated with operating a stacked-transistor silicon-on-insulatorpower amplifier topology in multiple modes of operation with arelatively large difference in supply voltage provided to the poweramplifier in different modes of operation. For instance, atriple-stacked-transistor silicon-on-insulator power amplifier topologyoperable in three power modes in which a lowest power-mode has a supplyvoltage that is about 60% below the supply voltage for a highest powermode can operate with desirable performance in accordance with theprinciples and advantages discussed herein.

Embodiments of this disclosure relate to using a common power amplifierfor multiple modes of operation. Using the same power amplifier forseveral power modes can be desirable, as this can prevent increased diearea and complications with matching networks and RF-signal routingassociated with using different power amplifiers for different powermodes.

Embodiments of this disclosure can be implemented withsemiconductor-on-insulator technology, such as silicon-on-insulatortechnology. Using silicon-on-insulator technology and stacked transistortopologies can enable power amplifiers to be implemented in relativelyinexpensive and relatively reliable technology. Moreover, the desirableperformance of low-noise amplifiers (LNAs) and/or multi-throw RFswitches in silicon-on-insulator technology can enable a stackedtransistor silicon-on-insulator power amplifier to be implemented aspart of a complete front end integrated circuit (FEIC) solution thatincludes transmit, receive, and switching functionality with desirableperformance.

FIG. 50 is a schematic diagram of a power amplifier system 1310. Theillustrated power amplifier system 1310 includes a power amplifier 1312,a bias circuit 1314, a supply control circuit 1315, switches 1316, anantenna 1317, a directional coupler 1318, and a transmitter 1319. Thepower amplifier system 1310 can operate in multiple modes of operation.The multiples modes of operation can include at least two differentmodes of operation in which the supply control circuit 1315 provides asupply voltage VSUP having different voltage levels to the poweramplifier 1312. The bias circuit 1314 can bias the power amplifier 1312differently in two or more of the at least two different modes ofoperation. A power amplifier circuit can include the power amplifier1312 and the bias circuit 1314. The illustrated transmitter 1319includes a baseband processor 1321, an I/Q modulator 1322, a mixer 1323,and an analog-to-digital converter (ADC) 1324. The transmitter 1319 canbe included in a transceiver that also includes circuitry associatedwith receiving signals from an antenna (for instance, the antenna 1317)over one or more receive paths.

The power amplifier 1312 can amplify an RF signal. The RF signal can beprovided by the I/Q modulator 1322 of the transmitter 1319. Theamplified RF signal generated by the power amplifier 1312 can beprovided to the antenna 1317 by way of the switches 1316. The amplifiedRF signal can have a substantially constant envelope in certainapplications. The amplified RF signal can have a variable envelope insome applications. Moreover, the power amplifier 1312 can provide anamplified RF signal that has a substantially constant envelope in onemode and a variable envelope in another mode. The power amplifier 1312can be operated in multiple modes, such as multiple power modes. Thepower amplifier 1312 can include a stacked transistor topology, such asany of the stacked topologies discussed herein. The power amplifier 1312can be implemented by silicon-on-insulator technology. The poweramplifier 1312 can include field effect and/or bipolar transistors.

The voltage level of the supply voltage VSUP provided to the poweramplifier 1312 can be different in different modes of operation. Thesupply control circuit 1315 can be any suitable circuit to provide thesupply voltage VSUP to the power amplifier 1312. The supply controlcircuit 1315 can include a direct current to direct current (DC-DC)converter, for example. The supply control circuit 15 can include anyother suitable switching regulator, such a buck and/or boost converterin certain implementations.

In certain implementations, the power amplifier 1312 is a multi-stagepower amplifier. The supply control circuit 1315 can provide differentsupply voltages for different stages of the multi-stage power amplifier.The voltage level of the supply voltage VSUP provided to an output stageof the power amplifier 1312 can be significantly lower (e.g., about 60%lower) in one mode of operation than in another mode of operation.Significant differences in the voltage level of the supply voltage canresult in reduced headroom operation that can drive a stacked transistorcircuit topology into early power compression. Early power compressioncan degrade performance of the power amplifier 1312. For instance, earlypower compression can reduce OP1 dB, PSAT, PAE, the like, or anycombination thereof of the power amplifier 1312.

The bias signal BIAS received by the power amplifier 1312 from the biascircuit 1314 can bias the power amplifier 1312 for operation in thevarious modes of the multiple modes. The bias circuit 1314 can beimplemented by any suitable bias circuit for the power amplifier 1312.The bias circuit 1314 can bias a transistor in a stacked transistorpower amplifier stage of the power amplifier 1312 to a linear region ofoperation in a first mode and bias the transistor in the stackedtransistor power amplifier stage as a switch in a second mode in whichthe voltage level of the supply voltage VSUP is significantly lower thanin the first mode. For instance, a common gate transistor (or a commonbase transistor in a bipolar implementation) of the stacked transistorpower amplifier stage can be operated in the linear region in the firstmode and turned ON hard to act as a switch in the second mode. This canreduce or eliminate the common gate transistor's effect on headroom whenthe transistor is biased as a switch. Accordingly, the OP1 dB and PSATcan be improved in the second mode.

In the illustrated power amplifier system 1310, the directional coupler1318 is coupled between the output of the power amplifier 1312 and theinput of the switches 1318, thereby allowing a measurement of outputpower of the power amplifier 1312 that does not include insertion lossof the switches 1317. The sensed output signal from the directionalcoupler 1318 can be provided to the mixer 1323, which can multiply thesensed output signal by a reference signal of a controlled frequency soas to downshift the frequency content of the sensed output signal togenerate a downshifted signal. The downshifted signal can be provided tothe ADC 1324, which can convert the downshifted signal to a digitalformat suitable for processing by the baseband processor 1321.

By including a feedback path between the output of the power amplifier1312 and the baseband processor 1321, the baseband processor 1321 can beconfigured to dynamically adjust the I and Q signals to optimize theoperation of the power amplifier system 1310. For example, configuringthe power amplifier system 1310 in this manner can aid in controllingthe power added efficiency (PAE) and/or linearity of the power amplifier1312.

The baseband signal processor 1321 can generate an I signal and a Qsignal, which can be used to represent a sinusoidal wave or signal of adesired amplitude, frequency, and phase. For example, the I signal canbe used to represent an in-phase component of the sinusoidal wave andthe Q signal can be used to represent a quadrature component of thesinusoidal wave, which can be an equivalent representation of thesinusoidal wave. In certain implementations, the I and Q signals can beprovided to the I/Q modulator 1322 in a digital format. The basebandprocessor 1321 can be any suitable processor configured to process abaseband signal. For instance, the baseband processor 1321 can include adigital signal processor, a microprocessor, a programmable core, or anycombination thereof. Moreover, in some implementations, two or morebaseband processors 1321 can be included in the power amplifier system1310.

The I/Q modulator 1322 can receive the I and Q signals from the basebandprocessor 1321 and to process the I and Q signals to generate an RFsignal. For example, the I/Q modulator 1322 can includedigital-to-analog converters (DACs) configured to convert the I and Qsignals into an analog format, mixers for upconverting the I and Qsignals to radio frequency, and a signal combiner for combining theupconverted I and Q signals into an RF signal suitable for amplificationby the power amplifier 1312. In certain implementations, the I/Qmodulator 1322 can include one or more filters configured to filterfrequency content of signals processed therein.

Transistor stacking can be implemented in silicon-on-insulator poweramplifiers. For instance, such transistor stacking can be implemented inthe power amplifier 1312 of FIG. 50. The transistor stacking canovercome relatively low breakdown voltages of scaled transistors,especially when exposed to voltage swing exceeding a voltage swing thatcan be accommodated by each transistor in the stacked such as 2.75Volts.

FIG. 51 is a graph illustrating a relationship between peak outputvoltage and direct current (DC) current for conduction angles of astacked amplifier at a fixed output power level.

FIG. 52A illustrates a stacked amplifier 1330 with three transistors inthe stack and a voltage swing of the stacked amplifier for a supplyvoltage. Stacking three transistors as shown in FIG. 52A can enablepower amplifier operation to work well with supply voltages betweenabout 3 Volts to 3.6 Volts and voltage swings approaching greater than 8Volts. For example, when each transistor in the stack can accommodate avoltage swing of up to about 2.75 Volts, the three stacked transistorscan together accommodate a voltage swing of up to about 8.25 Voltswithout experiencing significant hot carrier injection (HCl) andcorresponding long-term effects of reduced transistor drain current andincreased transistor leakage.

FIG. 52B illustrates a stacked amplifier 1335 with two transistors inthe stack and a voltage swing of the stacked amplifier for the samesupply voltage as FIG. 52A. Compared to the stacked amplifier 1330, thestacked amplifier 1335 can accommodate about two thirds of the voltageswing. As an example, when each transistor in the stacked amplifier 1335can accommodate a voltage swing of up to about 2.75 Volts, the twostacked transistors can together accommodate a voltage swing of up toabout 5.5 Volts without introducing significant HCl effects.Accordingly, the stacked amplifier 1335 may not be suitable forapplications with voltage swings of greater than 5.5 Volts in thisexample. As such, for applications with voltage swings of greater than5.5 Volts, three or more transistors can be included in series with eachother in a stacked amplifier.

For amplifiers operable with variable supply voltage levels in multiplepower modes, headroom can be reduced in lower power modes with lowersupply voltages. This can drive the stacked amplifier into earlycompression, which can reduce OP1 dB and PAE. By having at least oneless transistor in the stack, problems associated with reduced headroomcan be reduced or eliminated. Accordingly, the stacked amplifier 1335can be more suitable than the stacked amplifier 1330 when the supplyvoltage has a lower voltage level. Embodiments discussed herein relateto biasing stacked amplifiers such that they behave like the stackedamplifier 1330 in a first mode with a supply voltage having a relativelyhigh voltage level and such that they behave like the stacked amplifier1335 in a second mode with the supply voltage having a relatively lowvoltage level. As such, this biasing can enable the stacked amplifier toaccommodate a relatively high voltage swing when the supply voltage hasa relatively high voltage level and also to reduce or eliminate problemsassociated with headroom when the supply voltage has a relatively lowvoltage level.

FIG. 53A is a schematic diagram of a power amplifier system 1340 withconceptual biasing illustrated for two modes of operation of a stackedoutput stage according to an embodiment. The illustrated power amplifiersystem 1340 includes an input stage, an output stage, matching networks,and biasing circuit elements. The power amplifier system can receive anRF input signal PA_IN and provide an amplified RF output signal PA_OUT.The power amplifier 1312 of FIG. 50 can be implemented in accordancewith any of the principles and advantages of the power amplifier system1340.

As illustrated, the input stage includes a stacked amplifier implementedby transistors 1342 and 1343. Such an amplifier can be referred to as acascode amplifier. The stacked amplifier of the input stage can bebiased by conceptual biasing circuit elements R1 and R2. The conceptualbias circuit elements R1 and R2 can be implemented by any suitablebiasing circuit elements and can include circuitry in additional toand/or in place of the illustrated resistors. An AC grounding gatecapacitor C1 can be electrically connected to the common gate transistor1343. In some other implementations, the input stage can alternativelyinclude an injection-lockable power oscillator that can be frequency andphase locked to an input modulated signal. The input stage can receivean input stage supply voltage Vdd1. A parallel LC circuit including aninductor L1 and a capacitor C2 can provide the input stage supplyvoltage Vdd1 to the stacked amplifier of the input stage. The inputstage supply voltage Vdd1 can be substantially the same in differentmodes of operation.

The output stage of the illustrated power amplifier system 1340 is atriple-stacked amplifier. The illustrated output stage includes twocommon gate transistors 1345 and 1346 in series with a common sourcetransistor 1344. The transistors 1344, 1345, and 1346 can besilicon-on-insulator transistors. The transistor 1345 can be biased to alinear region of operation by conceptual biasing circuit element R4.Similarly, the transistor 1346 can be biased to a linear region ofoperation by conceptual biasing circuit element R3. The conceptual biascircuit elements R3 and R4 can be implemented by any suitable biasingcircuit elements and can include circuitry in additional to and/or inplace of the illustrated resistors. AC grounding gate capacitors C5 andC6 can be electrically connected to gates of the common gate transistors1346 and 1345, respectively. The transistor 1344 can be biased by abiasing circuit element R5. Such a triple-stacked output stage canprevent breakdown in modes of operation in which an output stage supplyvoltage Vdd2 is 3 Volts and 1.8 Volts, respectively, for example. In thecircuit illustrated in FIG. 53A, the output stage supply voltage Vdd2being 3 Volts corresponds to a first mode and the output stage supplyvoltage Vdd2 being 1.8 Volts corresponds to a third mode.

The power amplifier system 1340 can include matching networks forimpedance matching. The illustrated matching networks include an inputmatching network 1347, an inter-stage matching network 1348, and anoutput matching network 1349. In FIG. 53A, an input matching network1347 is electrically coupled between an input of the power amplifiersystem and the input stage. The inter-stage matching network 1348 caninclude any suitable circuit elements for inter-stage impedancematching. An inter-stage matching network between stages of poweramplifiers discussed herein can include a T-network and/or a pi-networkin certain applications. The illustrated inter-stage matching network1348 includes capacitors C3 and C4 and inductor L2 arranged as aT-network. The output matching network 1349 can be a class F outputmatching network, a class AB output matching network, a class B outputmatching network, or any other suitable output matching network. Theoutput stage of the power amplifier system 1340 can drive any suitableload.

FIG. 53B is a schematic diagram of the power amplifier system 1340 ofFIG. 53A with biasing illustrated for a second mode of operationaccording to an embodiment. The second mode of operation can be a lowerpower mode than the modes associated with the biasing in FIG. 53A. Asillustrated in FIG. 53B, the output stage supply voltage Vdd2 is 1.2Volts. The common gate transistor 1345 is biased so as to operate as aswitch instead of a common gate stage in FIG. 53B. The common gatetransistor 1345 can be turned ON hard enough such that its VDS issufficiently low (e.g., less than about 100 mV or less than about 75 mV)to make its effect on headroom insignificant. This can allow the PSAT toabout around 13 dBm in the second mode of operation in certainimplementations.

Accordingly, the power amplifier system 1340 can operate in at leastthree different power modes with different output stage supply voltages.In the example of FIGS. 53A and 53B, the output stage supply voltageVdd2 can be 3 Volts in a high power mode, the output stage supplyvoltage Vdd2 can be 1.8 Volts in a medium power mode, and the outputstage supply voltage Vdd2 can be 1.2 Volts in a low power mode. The highpower mode can be a first mode, the lower power mode can be a secondmode, and the medium power mode can be a third mode. The common gatetransistor 1345 can be biased to a linear region of operation in thehigh power mode and the medium power mode, as illustrated in FIG. 53A.In the low power mode, the common gate transistor 1345 can be biased toas a switch, as illustrated in FIG. 53B. As such, the same poweramplifier can be used in multiple power modes of operation while meetingperformance specifications for each of the multiple power modes.

FIG. 53C is a schematic diagram of a power amplifier system 1340′ withconceptual biasing illustrated for a first mode of operation accordingto an embodiment. FIG. 53D is a schematic diagram of the power amplifiersystem 1340′ of FIG. 53C with conceptual biasing illustrated for asecond mode of operation. The power amplifier system 1340′ is like thepower amplifier system 1340 of FIGS. 53A and 53B except that a supplycontrol circuit 1315′ is included. The supply control circuit 1315′ canimplement any suitable features of the supply control circuit 1315 ofFIG. 50. The supply control circuit 1315′ can provide the input stagesupply voltage Vdd1 and the output stage supply voltage Vdd2 to thepower amplifier. The input stage supply voltage Vdd1 can havesubstantially the same voltage level in different modes of operation.The supply control circuit 1315′ can provide the output stage supplyvoltage Vdd2 such that the output stage supply voltage Vdd2 has a highervoltage level in the first mode corresponding to FIG. 53C than in thesecond mode corresponding to FIG. 53D. The supply control circuit 1315′can include any suitable circuit configured to perform thisfunctionality. For instance, the supply control circuit 1315′ caninclude a DC-DC converter or any other suitable switching regulator,such a buck and/or boost converter in certain implementations.

FIGS. 53A to 53D show an embodiment of an output stage of a poweramplifier. FIGS. 54A to 57B illustrate embodiments of stacked amplifiersand bias circuits. Any of the principles and advantages discussed withreference to any of these figures can be implemented in the poweramplifier 1312 of FIG. 50 and/or the output stage of the power amplifiersystem 1340. Moreover, any of the principles and advantages of thestacked amplifiers and bias circuits discussed herein can be implementedin other contexts.

FIG. 54A is a schematic diagram of an amplification circuit 1350 thatincludes a stacked amplifier and a bias circuit in a first modeaccording to an embodiment. The stacked amplifier can amplify an RFsignal. A DC blocking capacitor 1351 can provide an RF signal to aninput of the stacked amplifier. As illustrated, the stacked amplifierincludes transistors 1352, 1353, and 1354 arranged in series with eachother. The transistors 1352, 1353, and 1354 can be silicon-on-insulatorfield effect transistors. The bias circuit 1355 can bias the transistorsof the stacked amplifier. The bias circuit 1355 can dynamically bias thetransistors of the stacked amplifier responsive to a control signalMODE. The stacked amplifier can receive bias signals by way of biasingcircuit elements 1356, 1357, and 1358. In the first mode, the biascircuit 1355 biases the transistor 1353 to a linear region of operation.The stacked amplifier can receive a supply voltage V_(dd) by way of aninductor 1359.

FIG. 54B is a schematic diagram of the amplification circuit 1350 ofFIG. 54A in a second mode according to an embodiment. The second modecan be associated with a lower power than the first mode. In the secondmode of operation, the supply voltage V_(dd) provided to the stackedamplifier can have a higher voltage level than in the first mode. Themode control signal MODE provided to the bias circuit 1355 can be at adifferent signal level and/or in a different state. Responsive to themode control signal MODE, the bias circuit 1355 can bias the transistor1353 as a switch. The transistor 1353 can operate in a saturation regionof operation in the second mode.

FIG. 55A is a schematic diagram of an amplification circuit 1360 thatincludes a stacked amplifier and a bias circuit in a first modeaccording to an embodiment. The amplification circuit 1360 is like theamplification circuit 1350 except the stacked amplifier is implementedby bipolar transistors. As illustrated in FIG. 55A, the stackedamplifier includes two common base transistors 1362 and 1363 in serieswith a common emitter transistor 1361. The bipolar transistorsillustrated in FIG. 55A can be implemented by semiconductor-on-insulatortechnology. Any suitable circuit topologies discussed and/or illustratedherein with field effect transistors can alternatively be implemented bybipolar transistors. According to some other embodiments, theamplification circuit 1360 can include an RF impedance, such as aninductor, disposed between the bias circuit 1355 and the base of thetransistor 1361 in place of the resistor illustrated in FIGS. 55A and55B. Alternatively or additionally, an amplification circuit with astacked bipolar amplifier can be implemented without resistors disposedbetween a bias circuit and one or more of the bipolar transistors of thestack.

FIG. 55B is a schematic diagram of the amplification circuit 1360 ofFIG. 55A in a second mode of operation according to an embodiment. Inthe second mode of operation, the transistor 1362 is biased as a switch.

FIG. 56A is a schematic diagram of an amplification circuit 1370 thatincludes stacked amplifier with four transistors in the stack and a biascircuit in a first mode according to an embodiment. The amplificationcircuit 1370 is like the amplification circuit 1350 except the stackedamplifier is implemented by four transistors that are in series witheach other. The stacked amplifier illustrated in FIG. 56A includestransistors 1352, 1353, 1371, and 1354. By having an additionaltransistor in the stack relative to the stacked amplifier shown in FIG.54A, the stacked amplifier in FIG. 56A can accommodate a larger voltageswing. The bias circuit 1355′ can bias the transistor 1371 by way of abiasing circuit element 1372. In the first mode, the transistors 1353and 1371 can be biased in a linear region of operation.

FIGS. 56B and 56C are schematic diagrams of the stacked amplifier andthe bias circuit of FIG. 56A in different modes according to anembodiment. As shown in FIG. 56B, the transistor 1353 can be biased as aswitch in a second mode. The stacked amplifier of FIG. 56B can behavelike a triple stack when the transistor 1353 is biased as a switch andthe other transistors of the stack are biased as gain stages. As shownin FIG. 56C the transistors 1353 and 1371 can be biased as switches inanother mode. The stacked amplifier of FIG. 56C can behave like a doublestack when the transistors 1353 and 1371 are biased as switches and theother transistors of the stack are biased as gain stages. Accordingly,the bias circuit 1355′ can bias the stacked amplifier of FIGS. 56A to56C to behave as if 2, 3, or 4 transistors are in the stack. Theprinciples and advantages discussed in this section can also be appliedto stacked amplifiers having five or more transistors in series witheach other.

FIG. 57A is a schematic diagram of an amplification circuit 1380 thatincludes a stacked amplifier with two transistors in the stack and abias circuit in a first mode according to an embodiment. Theamplification circuit 1380 is like the amplification circuit 1350 exceptthat the stacked amplifier is implemented by two transistors that are inseries with each other. As shown in FIG. 57A, the bias circuit 1355″ canbias the transistor 1353 to a linear region of operation in the firstmode.

FIG. 57B is a schematic diagram of the amplification circuit 1380 ofFIG. 57A in a second mode according to an embodiment. As shown in FIG.57A, the bias circuit 1355″ can bias the transistor 1353 in as a switchin the second mode.

FIG. 58A is a schematic diagram of a power amplifier system 1390 withbiasing illustrated for two modes of operation according to anembodiment. FIG. 58B is a schematic diagram of the power amplifiersystem 1390 of FIG. 58A with biasing illustrated for a different mode ofoperation according to an embodiment. The power amplifier system 1390 islike the power amplifier system 1340 except that additional switches1391, 1392, and 1393 are included and a different transistor in thestack can be biased as a switch in a mode associated with a lower outputstage supply voltage. Any suitable control circuit can control theswitches 1391, 1392, and 1393. In the power amplifier system 1390, thetransistor 1344 can be biased to operate as a common source amplifier asshown in FIG. 58A or as a switch as shown in FIG. 58B.

The switch 1391 can selectively electrically couple an output of theinput stage to different transistors of the output stage in differentmodes of operation. The switch 1391 can provide an RF input signal forthe output stage to the transistor 1344 in as shown in FIG. 58A. Theswitch 1391 can provide the RF input signal to the output stage to thetransistor 1345 in a different mode as shown in FIG. 58B. The switch1391 can be a multi-throw switch, such as a single pole double throwswitch.

The switch 1392 can maintain an RF inter-stage match. The switch 1392can electrically couple a capacitor C₇ to the gate of the transistor1345 to maintain the RF inter-stage match when the transistor 1344 isbiased as a switch as shown in FIG. 58B. When the transistor 1345 isbiased as a common gate amplifier as shown in FIG. 58A, the switch 1392can electrically disconnect the capacitor C₇ from the gate of thetransistor 1345.

The switch 1393 can electrically connects AC grounding gate capacitor C₆to the gate of transistor 1345 when the transistor 1345 is configured asa common gate amplifier as shown in FIG. 58A. The switch 1393 candisconnect AC grounding gate capacitor C₆ from the gate of transistor1345 when the transistor 1345 is configured as a common source amplifieras shown in FIG. 58B.

Any suitable combination of features of the power amplifier systems 1340and 1390 can be implemented together with each other. The poweramplifier 1312 of FIG. 50 can be implemented in accordance with any ofthe principles and advantages of the power amplifier system 1390. Thepower amplifier system 1390 can be implemented in accordance with any ofthe principles and advantages discussed herein, such as with referenceto any of FIGS. 54A to 57B.

The multi-mode power amplifiers discussed herein, which can be asdescribed earlier in this section, can be included in any suitable frontend system, packaged module, semiconductor die (e.g., asemiconductor-on-insulator die, such as a silicon-on-insulator die),wireless communication device (e.g., a mobile phone, such as a smartphone), or the like.

Section IV—Power Amplifier with Injection-Locked Oscillator Driver Stage

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to a power amplifier with aninjection-locked oscillator driver stage. In certain configurations, amulti-mode power amplifier includes a driver stage implemented using aninjection-locked oscillator and an output stage having an adjustablesupply voltage that changes based on a mode of the multi-mode poweramplifier. By implementing the multi-mode power amplifier in thismanner, the multi-mode power amplifier exhibits excellent efficiency,including when the voltage level of the adjustable supply voltage isrelatively low. As indicated above, aspects of this section may becombined with other aspects of one or more other sections to furtherimprove the performance of front end systems and related devices,integrated circuits, modules, and methods in which they are employed.

Certain power amplifiers are operable in multiple power modes.Implementing a power amplifier with multi-mode operation can provide anumber of advantages relative to an implementation including a separatepower amplifier associated with each power mode. For example, multi-modepower amplifiers can occupy a relatively small chip area. Additionally,multi-mode power amplifiers can avoid complications with matchingnetworks and signal routing associated with using a different poweramplifier for each power mode.

In mobile applications, prolonging battery lifetime can be significant.One function in mobile applications that consumes a significant amountof battery charge is power amplification.

A supply control circuit can provide a multi-mode power amplifier with asupply voltage that can vary or change depending on a mode of operationof the power amplifier. The mode of operation can be selected to achievedesired performance while increasing efficiency and/or extending batterylife. Thus, the supply control circuit can employ various powermanagement techniques to change the voltage level of the supply voltageto improve the power amplifier's power added efficiency (PAE).

One technique for improving power amplifier efficiency is to provide avariable supply voltage with selectable voltage levels based on powermode. For instance, a lower supply voltage can be provided in a lowerpower mode and a higher supply voltage can be provided in a higher powermode. The multi-mode power amplifier can include any suitable number ofsupply voltage levels and corresponding power modes, for instance, 2power modes, 3 power modes, or 4 or more power modes.

In certain configurations, a power amplifier includes multiple stagesand the supply voltage provided to a final or output stage can be varieddepending on the power mode while a different supply voltage for atleast one driver stage can remain substantially constant.

When a supply voltage for a power amplifier is reduced in a lower powermode for efficiency purposes, the supply voltage can be significantlylower than for a higher power mode. In one example, the supply voltagefor a lower power mode can be about 60% below the supply voltage for ahigher mode. However, other supply voltage levels are possible.

Apparatus and methods for power amplifiers with an injection-lockeddriver stage are provided herein. In certain configurations, amulti-mode power amplifier includes a driver stage implemented using aninjection-locked oscillator and an output stage having an adjustablesupply voltage that changes based on a mode of the multi-mode poweramplifier. By implementing the power amplifier in this manner, the poweramplifier can exhibit excellent efficiency, including when the voltagelevel of the adjustable supply voltage is relatively low.

For example, in a low power mode, the adjustable supply voltage used topower the output stage is decreased, and the driver stage has arelatively large impact on the power amplifier's overall efficiency. Byimplementing the driver stage using an injection-locked oscillator, theoverall efficiency of the multi-mode power amplifier is relatively highacross different power modes.

The multi-mode power amplifiers discussed herein can exhibit excellentefficiency in a variety of applications, such as applications in which adriver stage operates using a substantially fixed voltage and an outputstage operates with large differences in supply voltage across differentmodes of operation.

The power amplifiers disclosed herein can be implemented using a varietyof semiconductor processing technologies, including, but not limited to,semiconductor-on-insulator technology, such as silicon-on-insulator(SOI) technology. Using SOI technology can enable implementation ofpower amplifiers in a relatively inexpensive and/or reliablemanufacturing process. Moreover, desirable performance of low-noiseamplifiers (LNAs) and/or radio frequency (RF) switches in SOI technologyenables a power amplifier to be implemented as part of a front endintegrated circuit (FEIC) that provides transmit, receive, and switchingfunctionality.

FIG. 59 is a schematic diagram of one example of a power amplifiersystem 1426. The illustrated power amplifier system 1426 includes amulti-mode power amplifier 1432, a supply control circuit 1430, switches1412, an antenna 1414, a directional coupler 1424, and a transmitter1433.

The power amplifier system 1426 operates in multiple modes of operation.The multiple modes include at least two different modes of operation inwhich the supply control circuit 1430 provides a supply voltage ofdifferent voltage levels to the multi-mode power amplifier 1432.

The illustrated transmitter 1433 includes a baseband processor 1434 anI/Q modulator 1437, a mixer 1438, and an analog-to-digital converter(ADC) 1439. The transmitter 1433 can be included in a transceiver thatalso includes circuitry associated with receiving signals from anantenna (for instance, the antenna 1414 or a separate antenna) over oneor more receive paths.

The multi-mode power amplifier 1432 provides amplification to an RFsignal. As shown in FIG. 59, the RF signal can be provided by the I/Qmodulator 1437 of the transmitter 1433. The amplified RF signalgenerated by the multi-mode power amplifier 1432 can be provided to theantenna 1414 by way of the switches 1412. The multi-mode power amplifier1432 can include a driver stage implemented using an injection-lockedoscillator, such as any of the injection-locked oscillator topologiesdiscussed herein.

In certain implementations, the multi-mode power amplifier 1432 isimplemented using SOI technology. Implementing a power amplifier in thismanner aids in integrating the power amplifier with other circuitry,including, for example, the switches 1412.

As shown in FIG. 59, the multi-mode power amplifier 1432 receives afirst supply voltage V_(SUP1) for a driver stage and a second supplyvoltage V_(SUP2) for an output stage. In the illustrated embodiment, thesupply control circuit 1430 controls the voltage level of the secondsupply voltage V_(SUP2) based on a mode signal received from thetransmitter 1433. In certain configurations, the voltage level of thefirst supply voltage V_(SUP1) provided to the power amplifier's driverstage is substantially constant across two or more operating modes, butthe voltage level of the second supply voltage V_(SUP2) provided to thepower amplifier's output stage changes based on the selected operatingmode.

The supply control circuit 1430 can be any suitable circuit forproviding the first supply voltage V_(SUP1) and second supply voltageV_(SUP2) to the multi-mode power amplifier 1432. In certainconfigurations, the supply control circuit 1430 includes at least oneDC-to-DC converter, such as a buck converter, a boost converter, and/ora buck-boost converter.

In certain configurations, the voltage level of the second supplyvoltage V_(SUP2) can be significantly lower (e.g., about 60% lower) inone mode of operation relative to another mode of operation. Significantdifferences in the voltage level of the supply voltage can result indecreased efficiency.

The baseband signal processor 1434 can generate an I signal and a Qsignal, which can be used to represent a sinusoidal wave or signal of adesired amplitude, frequency, and phase. For example, the I signal canbe used to represent an in-phase component of the sinusoidal wave andthe Q signal can be used to represent a quadrature component of thesinusoidal wave, which can be an equivalent representation of thesinusoidal wave. In certain implementations, the I and Q signals can beprovided to the I/Q modulator 1437 in a digital format. The basebandprocessor 1434 can be any suitable processor configured to process abaseband signal. For instance, the baseband processor 1434 can include adigital signal processor, a microprocessor, a programmable core, or anycombination thereof. Moreover, in some implementations, two or morebaseband processors 1434 can be included in the power amplifier system1426.

The I/Q modulator 1437 can receive the I and Q signals from the basebandprocessor 1434 and to process the I and Q signals to generate an RFsignal. For example, the I/Q modulator 1437 can includedigital-to-analog converters (DACs) configured to convert the I and Qsignals into an analog format, mixers for upconverting the I and Qsignals to radio frequency, and a signal combiner for combining theupconverted I and Q signals into an RF signal suitable for amplificationby the multi-mode power amplifier 1432. In certain implementations, theI/Q modulator 1437 can include one or more filters configured to filterfrequency content of signals processed therein.

In the illustrated power amplifier system 1426, the directional coupler1424 is positioned between the output of the multi-mode power amplifier1432 and the input of the switches 1412, thereby allowing a measurementof output power of the multi-mode power amplifier 1432 that does notinclude insertion loss of the switches 1412. The sensed output signalfrom the directional coupler 1424 can be provided to the mixer 1438,which can multiply the sensed output signal by a reference signal of acontrolled frequency so as to downshift the frequency content of thesensed output signal to generate a downshifted signal. The downshiftedsignal can be provided to the ADC 1439, which can convert thedownshifted signal to a digital format suitable for processing by thebaseband processor 1434.

By including a feedback path between the output of the multi-mode poweramplifier 1432 and the baseband processor 1434, the baseband processor1434 can be configured to dynamically adjust the I and Q signals tooptimize the operation of the power amplifier system 1426. For example,configuring the power amplifier system 1426 in this manner can aid inproviding power control, compensating for transmitter impairments,and/or in performing digital pre-distortion (DPD). Although one exampleof a sensing path for a power amplifier is shown, other implementationsare possible.

FIG. 60 is a schematic diagram of one example of a multi-mode poweramplifier 1440. The multi-mode power amplifier 1440 includes a driverstage 1441, an output stage 1442, an input matching network 1443, aninterstage matching network 1444, and an output matching network 1445.

As shown in FIG. 60, the driver stage 1441 is powered by a first supplyvoltage V_(SUP1) and the output stage 1442 is powered by a second supplyvoltage V_(SUP2). The driver stage 1441 receives an RF input signal RFINvia the input matching network 1443, and generates an amplified RFsignal. The output stage 1442 receives the amplified RF signal via theinterstage matching network 1444, and further amplifies the amplified RFsignal to generate an RF output signal RFOUT.

FIGS. 61A-610 show graphs of simulation results for one example of themulti-mode power amplifier of FIG. 60. The graphs include simulationresults in a low power mode (13-dBm) in which V_(SUP1) is 1.8 V andV_(SUP2) is 1.2 V, a medium power mode (16-dBm) in which V_(SUP1) is 1.8V and V_(SUP2) is 1.8 V, and a high power mode (21-dBm) in whichV_(SUP1) is 1.8 V and V_(SUP2) is 3.0 V. The driver stage 1441 andoutput stage 1442 are each implemented using a common source amplifierwith SOI FETs.

Although FIG. 61A-610 illustrate simulation results of a multi-modepower amplifier, lab testing was also performed and yielded similarresults.

FIG. 61A shows a graph 50 of power added efficiency (PAE) and gainversus output power. The graph 1450 includes a first gain plot 1451 forthe low power mode, a second gain plot 1452 for the medium power mode,and a third gain plot 1453 for the high power mode. Additionally, thegraph 1450 includes a first PAE plot 1454 for the low power mode, asecond PAE plot 1455 for the medium power mode, and a third PAE plot1456 for the high power mode.

FIG. 61B shows a graph 1460 of current consumption versus output power.The graph 1460 includes a first driver stage current consumption plot1461 for the low power mode, a second driver stage current consumptionplot 1462 for the medium power mode, and a third driver stage currentconsumption plot 1463 for the high power mode. Additionally, the graph1460 includes a first output stage current consumption plot 1464 for thelow power mode, a second output stage current consumption plot 1465 forthe medium power mode, and a third output stage current consumption plot1466 for the high power mode. Furthermore, the graph 1460 includes afirst total current consumption plot 1467 for the low power mode, asecond total current consumption plot 1468 for the medium power mode,and a third total current consumption plot 1469 for the high power mode.

As shown in FIG. 61B, the driver stage and the output stage have arelatively comparable current consumption in the low power mode, whichleads to the driver stage having relatively large impact on overallefficiency. Moreover, since the supply voltage of the output stagedecreases to about 33% below that of the driver stage in this example,the output stage saturates at a lower output power level. Thus, bothpower gain and current consumption of the driver stage have a relativelylarge impact on overall efficiency in the low power mode.

Accordingly, efficiency of the driver stage is important for overall PAEin the low power mode.

FIG. 61C shows a graph 1470 of power level versus output power. Thegraph 1470 includes a second harmonic frequency power plot 1471 for thelow power mode, a second harmonic frequency power plot 1472 for themedium power mode, and a second harmonic frequency power plot 1473 forthe high power mode. Additionally, the graph 1470 includes a thirdharmonic frequency power plot 1474 for the low power mode, a thirdharmonic frequency power plot 1475 for the medium power mode, and athird harmonic frequency power plot 1476 for the high power mode.Furthermore, the graph 1470 includes a fundamental frequency power plot1477 for the low power mode, a fundamental frequency power plot 1478 forthe medium power mode, and a fundamental frequency power plot 1479 forthe high power mode.

In certain configurations herein, a multi-mode power amplifier includesa driver stage implemented using an injection-locked oscillator and anoutput stage having an adjustable supply voltage that changes with amode of the multi-mode power amplifier. By implementing the poweramplifier in this manner, the power amplifier can exhibit excellentefficiency, including in a low power mode. For example, in the low powermode, the adjustable supply voltage used to power the output stage isdecreased, and the driver stage has a relatively large impact on overallefficiency of the power amplifier. By implementing the driver stageusing an injection-locked oscillator, the overall efficiency of themulti-mode power amplifier is relatively high across different modes.

An RF system can include a separate power amplifier die to providedevices having higher efficiency and/or higher breakdown voltages. Forexample, an RF system can use a Gallium Arsenide (GaAs) die, a GalliumNitride (GaN) die, or a Silicon Germanium (SiGe) die in which a highimpedance load line provides relatively high voltage swing andrelatively low current consumption. However, using a separate poweramplifier die can increase the cost of the RF system and/or impactperformance of other components of the RF system. For example, it may bedesirable to implement the power amplifier in SOI technologies, since RFswitches and/or low noise amplifiers (LNAs) can exhibit superiorperformance when implemented using SOI processes relative to othertechnologies.

In certain configurations herein, an RF front-end integrated circuit(FEIC) is provided. The RF FEIC is fabricated using an SOI process, andincludes at least one LNA, at least one RF switch, and at least onepower amplifier. By integrating the power amplifier with the LNA and/orswitch, overall cost is reduced. Moreover, the LNA and/or RF switchexhibit superior performance relative to configurations in which the LNAand/or RF switch are fabricated using other processes. The poweramplifier can be integrated with the LNA and switch to provide afront-end for an RF transceiver on a single chip.

The multi-mode power amplifiers disclosed herein can provide enhancedperformance relative to a single-stage power amplifier that uses aninjection-locked oscillator. For example, an injection-locked oscillatorincludes an inductor-capacitor (LC) resonator or tank that isinjection-locked to an RF input signal. When the supply voltage of aninjection-locked oscillator is changed with operating mode, theinjection-locked oscillator can be detuned. For example, a change to thesupply voltage can shift the center frequency of oscillation and/orchange the range of frequencies that the oscillator can beinjection-locked to. This in turn can make the injection-lockedoscillator susceptible to undesired operation such as quasi-lock and/orfast-beat modes.

Accordingly, using an injection-locked oscillator driver stage with asubstantially constant supply voltage in combination with a variablesupply voltage output stage provides robust performance relative to asingle-stage power amplifier that uses an injection-locked oscillator.

FIG. 62A is a schematic diagram of a multi-mode power amplifier 1480according to one embodiment. The multi-mode power amplifier 80 includesan injection-locked oscillator driver stage 1481, an output stage 1442,an interstage matching network 1444, and an output matching network1445.

The injection-locked oscillator driver stage 1481 is powered by a firstsupply voltage VSUP1, and the output stage 1442 is powered by a secondsupply voltage VSUP2. The injection-locked oscillator driver stage 1481receives an RF input signal RFIN, and generates an amplified RF signal.The output stage 1442 receives the amplified RF signal via theinterstage matching network 1444, and further amplifies the amplified RFsignal to generate an RF output signal RFOUT.

Although the illustrated embodiment includes two stages, the multi-modepower amplifier 1480 can include one or more additional stages. Forexample, the multi-mode power amplifier can include a preceding stagebefore the injection-locked oscillator driver stage 1481 and/or anadditional stage included between the injection-locked oscillator driverstage 1481 and the output stage 1442.

As shown in FIG. 62A, the injection-locked oscillator driver stage 1481includes an input transformer or balun 1482, an output transformer orbalun 1483, a signal injecting circuit 1484, a negative transconductancecircuit 1485, and a capacitor 1486. Additionally, the capacitor 1486operates with an inductance of the output transformer 1483 in an LC tankor resonator.

The negative transconductance circuit 1485 provides energy to maintainthe LC tank in resonance. When injection-locked, the LC tank oscillatesat a frequency substantially equal to the frequency of the RF inputsignal RFIN. The output transformer 1483 serves to convert adifferential signal of the LC tank resonator to a single-ended signalsuitable for driving the input to the output stage 1442.

Configuring the injection-locked oscillator driver stage 1481 to providedifferential to single-ended signal conversion reduces or eliminates theimpact of output balun loss on overall power amplifier efficiencyrelative to an implementation including a fully differential outputstage.

In certain implementations, the capacitor 1486 includes a controllablecapacitance component, such as a variable and/or programmable capacitor.Providing controllable capacitance aids in tuning a range of frequenciesover which the injection-locked oscillator driver stage 1481 can belocked to. In addition to explicit capacitor structures, the capacitor1486 can also include one or more parasitic capacitances, such asparasitic diffusion capacitances of transistors of the negativetransconductance circuit 1485.

The injection-locked oscillator driver stage 1481 operates with very lowpower consumption relative to driver stages implemented as a commonsource or common emitter amplifier. During operation, theinjection-locked oscillator driver stage 1481 is locked in frequency andphase with respect to the RF input signal RFIN, and operates to generatean injection-locked RF signal. In certain configurations, the RF inputsignal RFIN is a modulated signal having a substantially constant signalenvelope.

In the illustrated embodiment, the first supply voltage VSUP1 operateswith a substantially constant voltage level across operating modes ofthe multi-mode power amplifier 1480. Thus, when the mode of themulti-mode power amplifier 1480 changes, the oscillation centerfrequency and associated locking range of the injection-lockedoscillator driver stage 1481 remains substantially unchanged.Configuring the multi-mode power amplifier 1480 provides robustperformance across different operating modes.

In contrast, a multi-mode power amplifier using an injection-lockedoscillator in an output stage can become detuned in response to supplyvoltage changes. For example, the oscillation center frequency and/ortuning range of such an injection-locked oscillator can change indifferent power modes, thereby degrading performance.

The illustrated injection-locked oscillator driver stage 1481 provides adifferential-to-single-ended signal conversion operation prior toamplification by the output stage 1442.

By implementing differential-to-singled-ended conversion in theinjection-locked oscillator driver stage 1481, superior power efficiencyperformance can be achieved. In particular, performing the conversion ata lower signal power level provides higher efficiency relative toperforming the conversion at a higher signal power level. For instance,a loss of L dB due to signal conversion has a larger impact at theoutput of the output stage 1442 relative to the same amount of loss atthe input of the output stage 1442.

The output stage 1442 can be implemented in a wide variety of ways. In afirst example, the output stage 1442 is implemented as a common sourceamplifier including an NMOS transistor having a gate that receives aninput signal, a source electrically connected to a ground voltage, and adrain that generates the RF output signal RFOUT. In a second example,the output stage 1442 is implemented as a cascode amplifier including astack of two or more NMOS transistors, and the input signal is providedto a gate of the bottommost transistor in the stack and the outputsignal is provided from a drain of the uppermost transistor in thestack.

Although various examples of the output stage 1442 have been described,the output stage 1442 can be implemented in a wide variety of ways,including, but not limited to, implementations using bipolar transistorsor implementations using a combination of field-effect transistors andbipolar transistors.

The interstage matching network 1444 provides impedance matching betweenthe output of the driver stage 1481 and an input to the output stage1442. Additionally, the output matching network 1445 provides outputimpedance matching to the output stage 1442. In certain implementations,the interstage matching network 1444 and/or the output matching network1445 provide harmonic termination, DC biasing, and/or aid in achieved adesired load line impedance.

Including the interstage matching network 1444 and the output matchingnetwork 1445 increase power transfer relative to a configuration inwhich the impedance matching networks are omitted. The impedancematching networks can be implemented in a wide variety of ways.

In the illustrated embodiment, the input transformer or balun 1482serves at least in part to provide input impedance matching, therebyreducing component count and/or area. However, other implementations arepossible.

Additional details of the multi-stage amplifier 1480 can be as describedherein.

FIG. 62B is a schematic diagram of a multi-mode power amplifier 1495according to another embodiment. The multi-mode power amplifier 1495 ofFIG. 62B is similar to the multi-mode power amplifier 1480 of FIG. 62A,except that the multi-mode power amplifier 1495 of FIG. 62B includes asupply control circuit 1490 that controls a voltage level of the secondsupply voltage VSUP2 based on a power mode signal. In the illustratedembodiment, the supply control circuit 1490 includes a DC-to-DCconverter 1491 for efficiently regulating the second supply voltageVSUP2 to a desired voltage level.

FIG. 63 is a schematic diagram of an injection-locked oscillator driverstage 1500 according to one embodiment. The illustrated injection-lockedoscillator driver stage 1500 includes an input transformer or balun1507, an output transformer or balun 1508, a first signal injectingn-type metal oxide semiconductor (NMOS) transistor 1501, a second signalinjecting NMOS transistor 1502, a first negative transconductance NMOStransistor 1503, a second negative transconductance NMOS transistor1504, and a bias NMOS transistor 1505.

As shown in FIG. 63, the injection-locked oscillator driver stage 1500receives a single-ended RF input signal IN and generates a single-endedRF output signal OUT. Additionally, the injection-locked oscillatordriver stage 1500 is powered using the first supply voltage V_(SUP1). Inthe illustrated embodiment, the first supply voltage V_(SUP1) isprovided to a center tap of a first winding of the output transformer1508.

The first and second negative transconductance NMOS transistors 1503,1504 are cross-coupled with one another, and operate as a negativetransconductance circuit. The first winding of the output transformer1508 is electrically connected between the drain of the first negativetransconductance NMOS transistor 1503 and the drain of the secondnegative transconductance NMOS transistor 1504.

The output transformer 1508 serves to convert a differential-endedsignal corresponding to a voltage difference between the drains of thenegative transconductance NMOS transistors 1503, 1504 to thesingle-ended injection-locked RF output signal OUT. In the illustratedembodiment, the singled-ended injection-locked RF output signal OUT isgenerated by a second winding of the output transformer 1508, and isreferenced to a ground voltage.

The injection-locked oscillator driver stage 1500 includes an LC tankassociated with the inductance of the output transformer 1508 and aparasitic capacitance at the drains of the negative transconductanceNMOS transistors 1503, 1504. In certain implementations, the LC tank ofthe injection-locked oscillator driver stage 1500 further includes anexplicit capacitor, such as controllable capacitance component toprovide tuning range.

The bias NMOS transistor 1505 controls a bias current of the negativetransconductance NMOS transistors 1503, 1504 and the LC tank'soscillation amplitude.

In the illustrated embodiment, the gate of the bias NMOS transistor 1505receives a bias voltage V_(BIAS), which controls the amount of biascurrent of the negative transconductance NMOS transistors 1503, 1504. Incertain implementations, the bias voltage V_(BIAS) is controllable, suchas by digital programming via an IC interface (for instance, a MIPI RFFEbus or I²C bus). The bias voltage V_(BIAS) can be provided to the gateof the bias NMOS transistor 1505 through a resistive feed to aid inproviding isolation to circuitry that generates the bias voltageV_(BIAS), which can be generated using any suitable bias circuitry.

The negative transconductance NMOS transistors 1503, 1504 provide energyto the LC tank to maintain oscillations. When the RF input signal IN isnot present, the oscillation frequency of the LC tank resonator can beabout equal to the LC tank's resonant frequency.

The input transformer 1507 serves to convert the single-ended RF inputsignal IN to a differential signal provided to the gates of the signalinjecting NMOS transistors 1501, 1502. As shown in FIG. 63, the drainsof the first and second signal injecting NMOS transistors 1501, 1502 areelectrically connected to the drains of the first and second negativetransconductance NMOS transistors 1503, 1504, respectively. When the RFinput signal IN is sufficiently large, the signal injecting NMOStransistors 1501, 1502 provide sufficient signal injection to lock theoscillation frequency and phase of the LC oscillator to the frequency ofthe RF input signal IN.

The injection-locked oscillator driver stage 1500 illustrates oneembodiment of a driver stage that can be used in the multi-mode poweramplifiers described herein. However, an injection-locked oscillatordriver stage can be implemented in other ways.

Additional details of the injection-locked oscillator driver stage 1500can be as described herein.

The multi-mode power amplifiers discussed herein, which can be asdescribed earlier in this section, can be included in any suitable frontend system, packaged module, semiconductor die (e.g., asemiconductor-on-insulator die, such as a silicon-on-insulator die),wireless communication device (e.g., a mobile phone, such as a smartphone), or the like.

Section V—Electrical Overstress Protection

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to electrical overstress (EOS) protectioncircuits. Such EOS protection circuits can divert charge associated withan EOS event away from a signal node to provide EOS protection. Asindicated above, aspects of this section may be combined with otheraspects of one or more other sections to further improve the performanceof front end systems and related devices, integrated circuits, modules,and methods in which they are employed.

To protect a pin or pad of an integrated circuit (IC) from electricaloverstress (EOS) events, the IC can include an EOS protection circuitconnected between the pad and ground. To prevent the EOS protectioncircuit from interfering with normal operation of the IC, it isdesirable for the EOS protection circuit to be turned off andnon-conducting when normal operating conditions or voltage levels arepresent at the pad, and to turn on and conduct to provide overstressprotection in response to an EOS event occurring.

Certain EOS protection circuits are implemented using a number ofseries-connected diodes between a pad and ground. For example, an EOSprotection circuit can include a number of diodes in series to provide atrigger voltage sufficiently above normal operating voltage levels ofthe pad. To prevent the EOS protection circuit from accidentallytriggering and conducting in the presence of normal operating voltagelevels, the number of series-connected diodes can be selected such thatthe resulting trigger voltage is safely above the maximum operatingvoltage of the pad.

However, such a protection scheme can limit and/or constrain EOSprotection. For example, the trigger voltage of an EOS protectioncircuit implemented with multiple diodes in series can be based on a sumof the forward voltages of the diodes. For instance, the trigger voltageof an EOS protection circuit with about n identical series-connecteddiodes can be about n*Vf, where Vf is the forward voltage of each diode.

A diode's forward voltage can reduce with temperature. To preventunintended activation at high temperatures by normal signaling, the EOSprotection circuit can be implemented with a minimum number of diodessufficient to avoid conduction under normal operating conditions.However, when a sufficient number of diodes are included to accommodateboth the maximum pad voltage during normal operation, a desired voltagemargin, process variation, and the maximum operating temperature of theIC, EOS protection is typically reduced at normal temperatures andconditions.

For example, when the EOS protection circuit is implemented in thismanner, the EOS protection circuit's trigger voltage can be relativelyhigh at normal operating temperatures, thereby resulting in an increasein peak voltage levels under ESD conditions and a correspondingdegradation in overstress protection.

Accordingly, providing EOS protection using only series-connected diodesto ground may be insufficient in certain applications, since too manyseries-diodes may be desired to avoid conduction under normal signalingconditions across process and/or temperature variations.

In other implementations, a diode is electrically connected between thepad and a power high supply voltage to provide EOS protection. However,during an EOS event, overstress current can flow into the power highsupply voltage. Although a clamp circuit can be used to limit a voltageincrease of the power high supply rail during an EOS event, the clampcircuit can decrease power performance by generating leakage current,which can be unacceptable in certain low power applications.

Apparatus and methods for EOS protection circuits are provided in thissection. In certain configurations, an EOS protection circuit includesan overstress sensing circuit electrically connected between a pad and afirst supply node, an impedance element electrically connected betweenthe pad and a signal node, a controllable clamp electrically connectedbetween the signal node and the first supply node and selectivelyactivatable by the overstress sensing circuit, and an overshoot limitingcircuit electrically connected between the signal node and a secondsupply node. The overstress sensing circuit activates the controllableclamp when an EOS event is detected at the pad. Thus, the EOS protectioncircuit can divert charge associated with the EOS event away from thesignal node to provide EOS protection.

In certain implementations, the overstress sensing circuit includes aplurality of series-connected diodes and a first field-effect transistor(FET), such as a first metal-oxide-semiconductor (MOS) transistor.Additionally, the controllable clamp includes a second FET, such as asecond MOS transistor, having a gate voltage that is controlled based ona gate voltage of the first FET. For example, the first and second FETscan be implemented as a current mirror. Under EOS conditions at the pad,current flows through the overstress sensing circuit's series-connecteddiodes, thereby turning on the first and second FETs and activating thecontrollable clamp.

Additionally, the inclusion of the impedance element between the pad andthe signal node should result in the voltage of the signal node beingless than that of the pad in response to a voltage increase at the pad.Additionally, the overshoot limiting circuit can hold the voltage at thesignal node to a relatively low value until the controllable clamp isactivated. Implementing the EOS protection circuit in this manner canreduce the peak current injected into the second supply node and reducevoltage overshoot at the signal node. The reduction in peak current canlead to a smaller supply clamp (for instance, a more compact circuitlayout) between the first and second supply nodes and a correspondingdecrease in the IC's static power dissipation.

Accordingly, the teachings in this section can be used to provideenhanced EOS protection. Additionally, protecting an IC's pads using oneor more of the EOS protection circuits described herein can lead to asmaller and/or lower leakage supply clamp.

In certain configurations, the first supply node corresponds to ground.In such configurations, the EOS protection circuit advantageously shuntscharge of the EOS event to a node exhibiting very low impedance and/orenhanced thermal dissipation relative to other supply nodes.

FIG. 64 is a schematic diagram of an IC 1610. As shown in FIG. 64, theIC 1610 can include one or more pins or pads 1601 that can be exposed toEOS conditions, such as an ESD event 1605. The IC 1610 can include atleast one EOS protection circuit 1602 implemented in accordance with theteachings herein. A wireless or mobile device can include one or more ofthe ICs of FIG. 64. The wireless device can include EOS protectioncircuits implementing one or more features of this section. For example,wireless device can include multiple semiconductor chips or ICs, and oneor more of the ICs can include EOS protection circuits implemented inaccordance with the teachings herein.

FIG. 65A is a schematic diagram of one example of a module 1660 that caninclude one or more EOS protection circuits. FIG. 65B is a cross sectionof the module 1660 of FIG. 65A taken along the lines 65B-65B. The module1660 includes a module substrate or laminate 1662, asilicon-on-insulator (SOI) die 1670, and bond wires 1678. In certainimplementations, the module 1660 corresponds to a front end module.

The module substrate 1662 includes a die attach pad 1664 and bond pads1666. As shown in FIG. 65A, the SOI die 1670 is attached to the dieattach pad 1664 of the module substrate 1662. As depicted in FIG. 65B,the module substrate 1662 can include a plurality of conductive andnon-conductive layers laminated together, and the die attach pad 1664and the bond pads 1666 can be formed from a conductive layer 1681disposed on the surface of the module substrate used to attach the SOIdie 1670.

The SOI die 1670 includes pads 1676 that can be exposed to EOS events,such as the ESD event 1605. At least a portion of the pads 1676 of theSOI die 1670 can include corresponding EOS protection circuits 1602implemented in accordance with the teachings herein.

FIG. 65C is a cross section of a module 1680 according to anotherembodiment.

The module 80 of FIG. 65C is similar to the module 1660 of FIGS.65A-65B, except that the module 1680 is implemented using a flip-chipconfiguration. For example, rather than using wire bonds to electricallyconnect the SOI die 1690 to the module substrate 1662, the SOI die 1690of FIG. 65C has been flipped upside down and attached to the modulesubstrate 1662 using bumps 1691, which can be solder bumps. At least aportion of the pads 1676 of the SOI die 1670 can include EOS protectioncircuits 1602 implemented in accordance with the teachings herein.

Accordingly, in certain implementations described herein, EOS protectioncircuits are included in a die implemented using a flip-chiparrangement.

Although FIGS. 65A-65C illustrate example modules including an SOI diethat includes one or more EOS protection circuits, the teachings hereinare applicable to other configurations of modules and/or dies.

FIG. 66A is a schematic diagram of an IC interface 1700 including an EOSprotection circuit according to one embodiment. The IC interface 1700includes a pad 1701, an internal circuit 1703, and an EOS protectioncircuit including an overstress sensing circuit 1711, an impedanceelement 1712, a controllable clamp 1713, and an overshoot protection orlimiting circuit 1714.

The IC interface 1700 can undesirably encounter EOS events, such as theESD event 1605 at the pad 1701. Absent a protection mechanism, the EOSevent 1605 can lead to IC damage, such as gate oxide rupture, junctionbreakdown, and/or metal damage. For example, the internal circuit 1703can include sensitive transistors and/or structures that can be damagedabsent an EOS protection mechanism.

As shown in FIG. 66A, the overstress sensing circuit 1711 iselectrically connected between the pad 1701 and a first supply node orrail V1. Additionally, the impedance element 1712 is electricallyconnected between the pad 1701 and a signal node 1702. Furthermore, thecontrollable clamp 1713 is electrically connected between the signalnode 1702 and the first supply node V1, and is selectively activatableby the overstress sensing circuit 1711. Additionally, the overshootlimiting circuit 1714 is electrically connected between the signal node1702 and a second supply node or rail V2.

The overstress sensing circuit 1711 is electrically connected to the pad1701, and detects when an EOS event, such as ESD event 1605, is receivedat the pad 1701. When the EOS event is detected, the overstress sensingcircuit 1711 activates the controllable clamp 1713 to provide a lowimpedance path between the signal node 1702 and the first supply nodeV1. Thus, the EOS protection circuit is arranged to divert chargeassociated with the EOS event away from the signal node 1702 to provideEOS protection.

The overstress sensing circuit 1711 and the controllable clamp 1713 canbe implemented in a wide variety of ways. In one embodiment, theoverstress sensing circuit 1711 includes a plurality of series-connecteddiodes and a first FET. Additionally, the controllable clamp 1713includes a second FET having a gate voltage controlled based on a gatevoltage of the first FET. When an EOS event is received at the pad 1701,current flows through the overstress sensing circuit's series-connecteddiodes, thereby activating the first and second FETs.

With continuing reference to FIG. 66A, the impedance element 1712 iselectrically connected between the pad 1701 and the signal node 1702.Thus, when an EOS event increases the voltage of the pad 1701 relativeto the first supply node V1, the impedance element 1712 provides avoltage drop that results in the voltage of the signal node 1702 beingless than that of the pad 1701. The illustrated EOS protection circuitfurther includes the overshoot limiting circuit 1714, which transitionsfrom high to low impedance when the voltage of the signal node 1702increases above the voltage of the second supply node V2 by a triggervoltage of the overshoot limiting circuit 1714.

Including the impedance element 1712 and the overshoot limiting circuit1714 can maintain the voltage level of the signal node 1702 relativelylow when an EOS event is present. In particular, the overshoot limitingcircuit 1714 holds or limits the voltage at the signal node 1702 to arelatively low level until the overstress sensing circuit 1711 activatesthe controllable clamp 1713. Additionally, the impedance element 1712provides a voltage drop that allows the overshoot limiting circuit 1714to maintain the signal node's voltage to a relatively low voltage leveleven when the EOS event causes the voltage of the pad 1701 to increaseto a relatively high voltage level.

Accordingly, the illustrated configuration of the impedance element 1712and the overshoot limiting circuit 1714 can aids maintaining the signalnode 1702 at a relatively low voltage level. Furthermore, the inclusionof the impedance element 1712 can reduce the amount of charge that isinjected into the second supply node V2 via the overshoot limitingcircuit 1714 relative to a configuration in which the signal node 1702is directly connected to the pad 1701. Accordingly, the illustratedconfiguration can exhibit a relatively small amount of peak currentinjection into the second supply node V2 and reduces voltage overshootof the signal node 1702 during an EOS event. In certain implementations,the reduction in peak current leads to a smaller supply clamp (forexample, the supply clamp 1757 of FIG. 66C) between the first and secondsupply nodes V1, V2 and a corresponding decrease in the IC's staticpower dissipation.

Additional details of the IC interface 1700 can be as described earlier.

FIG. 66B is a schematic diagram of an IC interface 1730 including an EOSprotection circuit according to another embodiment. The IC interface1730 includes a pad 1701, an internal circuit 1703, and an EOSprotection circuit including an overstress sensing circuit 1711, animpedance element 1712, a controllable clamp 1713, an overshoot limitingcircuit 1714, a first reverse protection circuit 1731, and a secondreverse protection circuit 1732.

The IC interface 1730 of FIG. 66B is similar to the IC interface 1700 ofFIG. 66A, except that the IC interface 1730 further includes the firstreverse protection circuit 1731 and the second reverse protectioncircuit 1732. In certain implementations, the overstress sensing circuit1711 is implemented to activate the controllable clamp 1713 in responseto detecting a positive polarity EOS event that increases the voltage ofthe pad 1701 relative to the first supply node V1.

In the illustrated embodiment, the first reverse protection circuit 1731and the second reverse protection circuit 1732 can protect the ICinterface 1730 against a negative EOS event that decreases the voltageof the pad 1701 relative to the first supply node V1. The first reverseprotection circuit 1731 is electrically connected between the pad 1701and the first supply node V1, and transitions from high to low impedancewhen the voltage of the pad 1701 falls below the voltage of the firstsupply node V1 by a trigger voltage of the first reverse protectioncircuit 1731. Additionally, the second reverse protection circuit 1732is electrically connected between the signal node 1702 and the firstsupply node V1, and transitions from high to low impedance when thevoltage of the signal node 1702 falls below the voltage of the firstsupply node V1 by a trigger voltage of the second reverse protectioncircuit 1732.

Although the illustrated IC interface 1730 of FIG. 66B includes tworeverse protection circuits, more or fewer reverse protection circuitscan be included. In one embodiment, the first reverse protection circuit1731 is included and the second reverse protection circuit 1732 isomitted. In another embodiment, the first reverse protection circuit1731 is omitted and the second reverse protection circuit 1732 isincluded.

Additional details of the IC interface 1730 can be as described earlier.

FIG. 66C is a schematic diagram of an IC interface 1750 including an EOSprotection circuit according to another embodiment. The IC interface1750 includes a pad 1701, an internal circuit 1703, and an EOSprotection circuit including an overstress sensing circuit 1711, animpedance element 1712, a controllable clamp 1713, an overshoot limitingcircuit 1714, and a supply clamp 1757.

The IC interface 1750 of FIG. 66C is similar to the IC interface 1700 ofFIG. 66A, except that the IC interface 1750 further includes the supplyclamp 1757. In certain implementations, the supply clamp 1757 can helplimit a voltage difference between the second supply node V2 and thefirst supply node V1 during an overstress event.

Additional details of the IC interface 1750 can be as described earlier.

FIG. 67 is one example of a graph 1790 of voltage versus time for theEOS protection circuit of FIG. 66A. The graph 1790 includes a plot 1791of the voltage of the signal node 1702 of FIG. 66A versus time.

The graph 1790 begins at time zero, in which an EOS event is received atthe pad 1701. The graph 1790 has been annotated to show an activationtime tACTIVATION, corresponding to a time at which the controllableclamp 1713 is activated or turned on by the overstress sensing circuit1711. The activation time tACTIVATION can be associated with a delay indetecting the EOS event and in providing a control voltage and/orcurrent of sufficient magnitude to activate the controllable clamp 1713.

As shown in FIG. 67, the voltage of the signal node 1702 can increaseduring a period of time in which the controllable clamp 1713 is notactivated. By including the impedance element 1712 and the overshootlimiting circuit 1714, the voltage overshoot VOVERSHOOT of signal node1702 can be decreased. Reducing voltage overshoot can provide enhancedprotection to the internal circuit 1703 and/or reduce charge injectionto the second supply node V2 via the overshoot limiting circuit 1714.

Although FIG. 67 illustrates one example of a graph of voltage versustime for the EOS protection circuit of FIG. 66A, other results arepossible. For example, simulated and/or measured results can vary basedon implementation and/or application.

FIG. 68A is a schematic diagram of an IC interface 1800 including an EOSprotection circuit according to another embodiment. The IC interface1800 includes an input pad 1801, an input logic circuit 1803, and an EOSprotection circuit including an overstress sensing circuit 1811, aresistor 1812, a controllable clamp 1813, an overshoot limiting circuit1814, a first reverse protection circuit 1815, a second reverseprotection circuit 1816, and a supply clamp 1817.

The IC interface 1800 can receive EOS events such as the ESD event 1605at the input pad 1801. Absent a protection mechanism, the EOS event canlead to IC damage, such as damage to the input logic circuit 1803 thatis electrically connected to the signal node 1802.

The illustrated EOS protection circuit provides bidirectional EOSprotection against both positive polarity EOS events that increase thevoltage of the input pad 1801 relative to the first supply node V1 andagainst negative polarity EOS events that decrease the voltage of theinput pad 1801 relative to the first supply node V1.

As shown in FIG. 68A, the overstress sensing circuit 1811 iselectrically connected between the input pad 1801 and a first supplynode V1. The overstress sensing circuit 1811 includes first to eighthdiodes 1821-1828, respectively, and a first n-type metal oxidesemiconductor (NMOS) transistor 1830. As shown in FIG. 68A, the first toseventh diodes 1821-1827 are electrically connected in series from anodeto cathode between the input pad 1801 and a drain of the first NMOStransistor 1830. Additionally, the eighth diode 1828 includes an anodeelectrically connected to a source of the first NMOS transistor 1830 anda cathode electrically connected to the first supply node V1. The firstNMOS transistor 1830 is diode-connected, and includes a gate and drainelectrically connected to one another.

The illustrated controllable clamp 1813 includes a second NMOStransistor 1831 and a clamp diode 1832. The second NMOS transistor 1831includes a drain electrically connected to the signal node 1802, and asource electrically connected to the first supply node V1 via the clampdiode 1832. Including the clamp diode 1832 in the controllable clamp1813 can aid in reducing the clamp's leakage current when normalsignaling conditions are present and the controllable clamp 1813 isturned off. As shown in FIG. 68A, the gate of the second NMOS transistor1831 of the controllable clamp 1813 is electrically connected to thegate of the first NMOS transistor 1830 of the overstress sensing circuit1811.

In the illustrated embodiment, the first NMOS transistor 1830 of theoverstress sensing circuit 1811 and the second NMOS transistor 1831 ofthe controllable clamp 1813 are connected as a current mirror. Althougha specific implementation of overstress sensing circuit and controllableclamp are shown, the teachings herein are applicable to a wide varietyof overstress sensing circuits and controllable clamps.

The overstress sensing circuit 1811 activates the controllable clamp1813 when a positive polarity EOS event is detected at the input pad1801. For example, when the voltage at the input pad 1801 issufficiently high, a current can flow through the first to eighth diodes1821-1828 and the first NMOS transistor 1830, thereby controlling thegate voltage of the first NMOS transistor 1830 to a sufficient voltageto turn on the second NMOS transistor 1831. The activation voltage ofthe overstress sensing circuit 1811 can be based on a forward voltage ofthe diodes 1821-1828 and a threshold voltage of the first NMOStransistor 1830.

As shown in FIG. 68A, the resistor 1812 is electrically connectedbetween the input pad 1801 and the signal node 1802. Additionally, theovershoot limiting circuit 1814 is electrically connected between thesignal node 1802 and the second supply node V2. In the illustratedconfiguration, the overshoot limiting circuit 1814 includes an overshootlimiting diode 1841 including an anode electrically connected to thesignal node 1802 and a cathode electrically connected to the secondsupply node V2. Implementing the overshoot limiting circuit 1814 in thismanner can provide the overshoot limiting circuit 1814 with a relativelylow trigger voltage that is about equal to a forward voltage of theovershoot limiting diode 1841. However, other configurations arepossible, such as implementations selected based on signaling levelsand/or processing constraints.

When an EOS event increases the voltage of the input pad 1801 relativeto the first supply node V1, the resistor 1812 provides a voltage dropthat results in the voltage of the signal node 1802 being less than thatof the input pad 1801. Including the resistor 1812 and the overshootlimiting circuit 1814 can maintain the voltage level of the signal node1802 relatively low when an EOS event is present. In particular, theovershoot limiting circuit 1814 holds the voltage at the signal node1802 to a relatively low level until the overstress sensing circuit 1811activates the controllable clamp 1813. Additionally, the resistor 1812provides a voltage drop that allows the overshoot limiting circuit 1814to maintain the signal node's voltage to a relatively low voltage leveleven when the EOS event causes the voltage of the input pad 1801 toincrease to a relatively high voltage level.

Furthermore, the inclusion of the resistor 1812 can reduce the amount ofcharge that is injected into the second supply node V2 via the overshootlimiting circuit 1814 relative to a configuration in which the signalnode 1802 is directly connected to the input pad 1801. Accordingly, theillustrated configuration can exhibit a relatively small amount of peakcurrent injection into the second supply node V2 and reduces voltageovershoot of the signal node 1802 during an EOS event. The reduction inpeak current leads to a reduction in a size of the supply clamp 1817 anda corresponding decrease in leakage current.

In the illustrated embodiment, the resistor 1812 is an explicit resistor(for instance, a thin-film resistor), and corresponds to more than mereparasitic resistance.

The illustrated EOS protection circuit further includes the firstreverse protection circuit 1815 and the second reverse protectioncircuit 1816, which aid in providing protection against negativepolarity EOS events that decrease the voltage of the input pad 1801relative to the first supply node V1. In the illustrated embodiment, thefirst reverse protection circuit 1815 includes a diode 1851 including ananode electrically connected to the first supply node V1 and a cathodeelectrically connected to the input pad 1801. Additionally, the secondreverse protection circuit 1816 includes a diode 1852 including an anodeelectrically connected to the first supply node V1 and a cathodeelectrically connected to the signal node 1802. However, otherconfigurations are possible.

Additional details of the IC interface 1800 can be as described earlier.

FIG. 68B is a schematic diagram of an IC interface 1900 including an EOSprotection circuit according to another embodiment. The IC interface1900 includes an input pad 1701, an input logic circuit 1803, and an EOSprotection circuit including an overstress sensing circuit 1911, aresistor 1812, a controllable clamp 1913, an overshoot limiting circuit1914, a first reverse protection circuit 1915, a second reverseprotection circuit 1816, and a supply clamp 1817.

The EOS protection circuit of FIG. 68B is similar to the EOS protectioncircuit of FIG. 68A, except that the EOS protection circuit of FIG. 68Bincludes different implementations of certain circuits.

For example, in the embodiment illustrated in FIG. 68B, the overstresssensing circuit 1911 includes first to eight diodes 1921-1928,respectively, and a first NMOS transistor 1930. The first to eightdiodes 1921-1928 are electrically connected in series from anode tocathode between the input pad 1801 and the first supply node V1, andcontrol a voltage at which the overstress sensing circuit 1911 detectsoverstress. Additionally, the first NMOS transistor 1930 includes adrain and gate electrically connected to the anode of the seventh diode1927, and a source electrically connected to a cathode of the seventhdiode 1927.

The illustrated controllable clamp 1913 of FIG. 68B includes the secondNMOS transistor 1931 and clamp diode 1932, which can be similar to thesecond NMOS transistor 1831 and clamp diode 1832 described earlier withrespect to FIG. 68A. The controllable clamp 1913 of FIG. 68B furtherincludes the capacitor 1933, which is electrically connected between thegate of the second NMOS transistor 1931 and the first supply node V1.The capacitor 1933 can aid in stabilizing a control voltage used toactivate the controllable clamp 1913, thereby helping to preventunintended activation.

The illustrated overshoot limiting circuit 1914 of FIG. 68B includes afirst diode 1941 and a second diode 1942 electrically connected inseries from anode to cathode between the signal node 1802 and the secondsupply node V2. Although the overshoot limiting circuit 1914 includestwo diodes in series, more or fewer diodes can be included. Moreover,other implementations of overshoot limiting circuits are possible, suchas implementations selected based on signaling levels and/or processingconstraints.

The illustrated first reverse protection circuit 1915 includes first tofourth diodes 1951-1954 electrically connected in series from anode tocathode between the first supply node V1 and the input pad 1801.However, other configurations are possible, including, but not limitedto, implementations with more or fewer diodes in series.

Additional details of the IC interface 1900 can be as described earlier.

The electrical overstress protection circuits discussed herein, whichcan be as described earlier in this section, can be included in anysuitable front end system, packaged module, semiconductor die (e.g., asemiconductor-on-insulator die, such as a silicon-on-insulator die),wireless communication device (e.g., a mobile phone, such as a smartphone), or the like. For example, a front end system can include one ormore semiconductor chips or ICs that include EOS protection circuitsimplemented in accordance with the teachings herein. Any of theprinciples and advantages of the EOS protection circuits discussedherein can be implemented in combination with any other suitablefeatures discussed herein that could benefit from an EOS protectioncircuits.

Section VI—Selective Shielding of Radio Frequency Modules

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to selectively shielded radio frequencymodules. A radio frequency module can include a package substrate, aradio frequency shielding structure extending above the packagesubstrate, a radio frequency component over the package substrate and inan interior of the radio frequency shielding structure, and an antennaon the package substrate external to the radio frequency shieldingstructure. The shielding structure can include a shielding layerproviding a shield over the radio frequency component and leaving theradio frequency module unshielded over the antenna. As indicated above,aspects of this section may be combined with other aspects of one ormore other sections to further improve the performance of front endsystems and related devices, integrated circuits, modules, and methodsin which they are employed.

Certain radio frequency (RF) modules can include a shielding structureto provide shielding for electromagnetic interference. Some suchshielding structures can shield an entire module and/or all circuitry ofa module. In certain instances, shielding may only be desired over aportion of a module. For instance, in a module with an RF circuit and anintegrated antenna, it can be desirable to provide a shield around theRF circuit and leave the antenna unshielded. This can provide RFisolation for the RF circuit and also allow the antenna to receiveand/or transmit signals without the shielding structure interfering.Accordingly, products with selective shielding can be desirable.Moreover, methods to form a shield over a selected portion of a modulethat are accurate and repeatable can be desirable for high volumemanufacturing.

Aspects of this section relate to methods of partially shielding a radiofrequency module. Such methods can include forming a shielding layerover a shielded portion of the radio frequency module and leaving anunshielded portion of the radio frequency module unshielded. Theshielding layer can shield a radio frequency circuit of the radiofrequency module and leave an antenna of the radio frequency moduleunshielded. The shielding layer can be formed by way of an additiveprocess or a subtractive process. For instance, the shielding layer canbe formed by masking a portion of the radio frequency module with amask, forming a shielding layer, and removing the mask so as to leavethe area that was previously masked unshielded. As another example, theshielding layer can be formed by forming a conductive layer over themodule and removing the conductive layer over a portion of the radiofrequency module. A laser can be used to remove the conductive layerover the portion of the radio frequency module.

Another aspect of this section is a packaged radio frequency (RF) modulethat is partially shielded. The RF module includes a package substrate,an RF shielding structure extending above the package substrate, an RFcomponent over the package substrate and in an interior of the RFshielding structure, and an antenna on the package substrate external tothe RF shielding structure.

FIG. 69 is a schematic diagram of an example RF module 2010 thatincludes an RF component 2012 and an integrated antenna 2014 accordingto an embodiment. The RF module 2010 can be a system in a package. FIG.69 shows the RF module 2010 in plan view without a top shielding layer.The top shielding layer can be formed, for example, in accordance withany of the processes described with reference to FIG. 72A, FIG. 73A,FIG. 74A, FIG. 75A, or FIG. 76A. As illustrated, the RF module 2010includes the RF component 2012 on a package substrate 2016, the antenna2014 on the package substrate 2016, and wire bonds 2018 attached to thepackage substrate 2016 and surrounding the RF component 2012. Theantenna 2014 of the RF module 2010 is outside of an RF shieldingstructure around the RF component 2012. Accordingly, the antenna 2014can wirelessly receive and/or transmit RF signals without being shieldedby the shielding structure around the RF component 2012. At the sametime, the shielding structure can provide RF isolation between the RFcomponent 2012 and the antenna 2014 and/or other electronic components.

The RF component 2012 can include any suitable circuitry configured toreceive, process, and/or provide an RF signal. For instance, the RFcomponent 2012 can include an RF front end, a crystal, a system on achip, or any combination thereof. In certain implementations, the RFcomponent 2012 can include a power amplifier, a low-noise amplifier, anRF switch, a filter, a matching network, a crystal, or any combinationthereof. An RF signal can have a frequency in the range from about 30kHz to 300 GHz. In accordance with certain communications standards, anRF signal can be in a range from about 450 MHz to about 6 GHz, in arange from about 700 MHz to about 2.5 GHz, or in a range from about 2.4GHz to about 2.5 GHz. In certain implementations, the RF component 2012can receive and/or provide signals in accordance with a wirelesspersonal area network (WPAN) standard, such as Bluetooth, ZigBee,Z-Wave, Wireless USB, INSTEON, IrDA, or Body Area Network. In some otherimplementations, the RF component and receive and/or provide signals inaccordance with a wireless local area network (WLAN) standard, such asWi-Fi.

The antenna 2014 can be any suitable antenna configured to receiveand/or transmit RF signals. The antenna 2014 can be a folded monopoleantenna in certain applications. The antenna 2014 can be any suitableshape. For instance, the antenna 2014 can have a meandering shape asshown in FIG. 69. In other embodiments, the antenna can be U-shaped,coil shaped, or any other suitable shape for a particular application.The antenna 2014 can transmit and/or receive RF signals associated withthe RF component 2012. The antenna 2014 can occupy any suitable amountof area of the packaging substrate 2016. For instance, the antenna 2014can occupy from about 10% to 75% of the area of the package substrate2016 in certain implementations.

The antenna 2014 can be printed on the packaging substrate 2016. Aprinted antenna can be formed from one or more conductive traces on thepackaging substrate 2016. The one or more conductive traces can beformed by etching a metal pattern on the packaging substrate 2016. Aprinted antenna can be a microstrip antenna. Printed antennas can bemanufactured relatively inexpensively and compactly due to, for example,their 2-dimensional physical geometries. Printed antennas can have arelatively high mechanical durability.

The package substrate 2016 can be a laminate substrate. The packagesubstrate 2016 can include one or more routing layers, one or moreinsulating layers, a ground plane, or any combination thereof. Incertain applications, the package substrate can include four layers. TheRF component 2012 can be electrically connected to the antenna 2014 byway of metal routing in a routing layer of the packaging substrate 2016in certain applications.

The wire bonds 2018 are part of an RF shielding structure around the RFcomponent 2012. An RF shielding structure can be any shielding structureconfigured to provide suitable shielding associated with RF signals. Thewire bonds 2018 can provide RF isolation between the antenna 2014 andthe RF component 2012 so as to prevent electromagnetic interferencebetween these components from significantly impacting performance of theantenna 2014 and/or the RF component 2012. The wire bonds 2018 cansurround the RF component 2012 as illustrated. The wire bonds 2018 canbe arranged around the RF component 2012 in any suitable arrangement,which can be rectangular as illustrated or non-rectangular in some otherimplementations. In the RF module 2010 illustrated in FIG. 69, the wirebonds 2018 form four walls around the RF component 2012. The wire bonds2018 can be arranged such that adjacent wire bonds are spaced apart fromeach other by a distance to provide sufficient RF isolation between theRF component 2012 and other electronic components.

FIG. 70 is a cross sectional view of the radio frequency module 2010 ofFIG. 69 prior to forming a shielding layer over the radio frequencycomponent 2012 according to an embodiment. As illustrated in FIG. 70,molding material 2022 can be disposed over the RF component 2012, thewire bonds 2018, and the antenna 2014. In FIG. 70, the RF component 2012includes two die 2012A and 2012B on the package substrate 2016. Upperportions 2023 of wire bonds 2018 can extend above upper surface 2024 ofan overmold structure of the molding material 2022 that is otherwiseover the wire bonds 2018. The wire bonds 2018 can extend above the uppersurface 2024 to a top point 2025 of the wire bonds 2018. The upperportions 2023 of the wire bonds 2018 can be exposed by removing moldingmaterial after forming an overmold structure of the molding material2022. Having the upper portions 2023 of the wire bonds 2018 exposed asshown in FIG. 70 can allow a conductive layer over the molding material2022 to be in contact with the wire bonds 2018 to thereby provide anelectrical connection. FIG. 70 also illustrates vias 2026 in the packagesubstrate 2016. The wire bonds 2018 can be electrically connected to aground plane 2027 of the package substrate 2016 by way of the vias 2026.The wire bonds 2018 can be electrically connected to a ground contact ofa system board on which the module 2010 is disposed by way of the vias2026.

FIG. 71 is a cross sectional view of the radio frequency module of FIG.69 with a shielding layer over the radio frequency component and notover the antenna according to an embodiment. The RF module 2010′illustrated in FIG. 71 includes a shielding layer 2032 formed over theupper surface 2024 of the overmold structure over the RF component 2012.The shielding layer 2032 is formed over a shielded portion of the RFmodule 2010′ and an unshielded portion of the RF module 2010′ is leftunshielded opposite the package substrate 2016. As illustrated, theantenna 2014 is included in the unshielded portion of the RF module2010′. The shielding layer 2032 is formed of electrically conductivematerial. As shown in FIG. 71, the shielding layer 2032 is in contactwith wire bonds 2018.

A shielding structure around the RF component 2012 includes theshielding layer 2032 and the wire bonds 2018. The shielding structurecan also include vias 2026 in the package substrate 2016, a ground plane2027 in the package substrate 2016, ground pads and/or a ground plane ofa system board on which the RF module 2010 is disposed, or any suitablecombination thereof. The RF shielding structure can function as aFaraday cage around the RF component 2012. The RF shielding structurecan be configured at a ground potential. The RF shielding structurearound the RF component 2012 can shield the RF component 2012 fromsignals external to the shielding structure and/or shield circuitsoutside of the shielding structure from the RF component 2012. Theantenna 2014 is external to the shielding structure in FIG. 71.

A shielding layer, such as the shielding layer 2032 of FIG. 71, can beformed over a portion of an RF module and a different portion of the RFmodule can be unshielded opposite a package substrate. Prior to formingthe shielding layer over an RF module in methods of forming theshielding layer discussed herein, the RF module can have moldingmaterial over an antenna and wire bonds with exposed upper portions thatextend beyond of surface of an overmold structure of the moldingmaterial (e.g., as shown in FIG. 70). Examples methods of forming such ashielding layer will be discussed with reference to FIGS. 72A to 76I. RFmodules discussed herein can include a shielding layer formed by any ofthese methods as appropriate and/or by any suitable operations discussedwith reference to any of these methods. The shielding layer can beformed over a selected portion of an RF module by an additive process ora subtractive process. The methods of forming shielding layers discussedherein can be implemented in high volume manufacturing. Such methods canbe automated in an accurate and repeatable manner.

FIG. 72A is a flow diagram of an illustrative process 2040 that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment. Theprocess 2040 involves forming a shielding layer over a portion of an RFmodule by a subtractive method. In the process 2040, a shielding layercan be formed over a plurality of RF modules, such as RF modules of astrip, concurrently. A conductive layer can be formed over the RFmodules and the conductive layer can be removed over a selected portionof each of the RF modules using a laser. Methods of forming a shieldinglayer involving laser removal of a portion of a conductive layer can beadvantageous for manufacturing RF modules that are relatively small insize. FIGS. 72B to 72E illustrate an example module or strip of modulescorresponding to various stages of the process of FIG. 72A according toan embodiment.

At block 2042, RF modules that include an RF component and an integratedantenna are provided. The RF modules can include one or more conductivefeatures, such as wire bonds, disposed between the RF component and theantenna. The conductive features are RF isolation structures that areincluded in a shielding structure. FIG. 72B illustrates an example RFmodule 2010A that can be provided at block 2042. The RF module 2010A cancorrespond to the RF module 2010 of FIGS. 69 and 70. As illustrated, theRF module 2010A of FIG. 72B includes an RF component 2012 that includescomponents 2012A, 2012B, and 2012C. As also illustrated in FIG. 72B, thewire bonds 2018 can surround the RF component. Upper portions of thewire bonds 2018 can be exposed, for example, as illustrated in FIG. 70.

A conductive layer can be formed over RF modules at block 2044. Theconductive layer can be in contact with wire bonds of the RF modules.The conductive layer can be a conformal layer formed by physical vapordeposition (PVD). A conductive material can be sputtered over a strip ofRF modules. A strip of RF module can be any suitable array of multipleRF modules that are processed together. Sputtering can provide aconductive layer than is smoother than conductive layers formed by someother processes. The conductive material layer can include any suitableconductive material for RF shielding. For example, the conductivematerial can be copper. Copper can provide desirable electromagneticinterference shielding and copper is also relatively inexpensive.Another example conductive material for the conductive layer is tungstennickel. A protective layer can be formed over the conductive layer. Thiscan prevent corrosion of the conductive layer. As an example, a titaniumlayer can be provided over a copper conductive layer to protect thecopper. FIG. 72C shows a strip of RF modules 2043 with a conductivelayer 2041 formed over the entire upper surface of the strip of RFmodules 2043.

At block 2046, the conductive layer can be removed over an antenna of anRF module. For instance, a laser can remove the conductive layer overthe antenna of the RF module. The laser can remove any suitable portionof the conductive layer over the RF module. Laser beams can be appliedconcurrently to two or more RF modules of the group of RF modules. Forinstances, portions of the conductive layer over an antenna of each ofthe RF modules of the strip of RF modules can be removed concurrently.In some instances, laser beams can be applied sequentially to differentRF modules of the group of RF modules. Removing a portion of theconductive layer with a laser can leave features on the RF module. Forexample, burn features, such as a halo ring, can be present on an RFcomponent after laser removal of a portion of the conductive layer.Laser removal can result in a rougher surface finish over the antennarelative to some other methods of forming a partially shielded RFmodule, such as methods that involve masking.

FIG. 72D shows a laser beam 2045 being applied to an RF module to removea portion of the conductive layer 2041. The laser can selectively removethe conductive layer over the RF module such that the RF module is leftwith an unshielded portion 2047 and a shielded portion 2049.Accordingly, a shielding layer can be disposed over the RF component andthe antenna can be unshielded opposite the package substrate. As such,the antenna can transmit and/or receive RF signals without the shieldinglayer interfering. While FIG. 72D illustrates the laser beam 2045 beingapplied to one module, laser beams can be applied to a group of RFmodules at block 2046 of the process 2046.

Referring to FIG. 72A, the strip of RF modules can be singulated intoindividual RF modules at block 2048. Accordingly, singulation can occurafter forming a shielding layer over a portion of an RF module. FIG. 72Eshows a singulated RF module 2010A′ that includes a shielding layer overa portion of the packaging substrate.

FIG. 73A is a flow diagram of an illustrative process 2050 that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment. Theprocess 2050 involves forming a shielding layer over a portion of an RFmodule by an additive method. In the process 2050, masking material canbe applied over selected portions of a plurality of RF modules of astrip, a conductive layer can be formed over the RF modules and themasking material, and the masking material can be removed. Methods offorming a shielding layer involving masking can be advantageous formanufacturing RF modules that are relatively large in size and/or forforming a shielding layer for a relatively small number of RF modulesconcurrently. FIGS. 73B to 73F illustrate an example module or strip ofmodules corresponding to various stages of the process of FIG. 73Aaccording to an embodiment.

At block 2051, RF modules that include an RF component and an integratedantenna are provided. The RF modules can include one or more conductivefeatures, such as wire bonds, disposed between the RF component and theantenna. The conductive features are RF isolation structures that areincluded in a shielding structure. FIG. 73B illustrates an example RFmodule 2010A that can be provided at block 2051. The RF module 2010A cancorrespond to the RF module 2010 of FIGS. 69 and 70. The RF module 2010Aof FIG. 73B can also correspond to the RF module 2010A of FIG. 72B. Asillustrated, the RF module 2010A of FIG. 73B includes an RF component2012 that includes components 2012A, 2012B, and 2012C. As alsoillustrated in FIG. 73B, the wire bonds 2018 can surround the RFcomponent.

A masking material can be provided over selected portions of RF modulesat block 2053. A strip of RF modules can be masked concurrently and/orsequentially at block 2053. The masking material can be relatively hightemperature tape. The masking material can be applied over the antennaof each of the RF modules of a strip of RF modules. FIG. 73C shows astrip 2052 of RF modules with masking material 2054 formed over aselected portion of each RF module of the strip 2052.

At block 2055, a conductive layer is formed over the strip of RFmodules. The conductive layer can be in contact with wire bonds of theRF modules. The conductive layer can be formed by way of PVD or sprayingconductive material over the strip of RF modules. For example, theconductive layer can be formed in accordance with any of the principlesand advantages discussed with reference to block 2044 of the process2040. As another example, the conductive layer can be formed by sprayingconductive paint, such as silver (Ag) based conductive paint, over thestrip of RF modules. FIG. 73D shows a strip 2052′ of RF modules with atop surface covered by a conductive layer 2041.

The masking material is removed at block 2057. For instance, tape can beremoved in any suitable manner. By removing the masking material,portions of the conductive layer that were formed over the maskingmaterial are also removed. Accordingly, the portion of the RF modulethat was covered by the masking material can be unshielded opposite thepackaging substrate. Removing the masking material can leave features onthe RF module. For example, a whisker feature and/or a relatively sharpstep can be present from removing the masking material. FIG. 73E shows astrip 2052″ of RF modules with a top surface having shielded portions2049 and unshielded portions 2047. In the shielded portions 2049, ashielding layer 2032 is included in a shielding structure around the RFcomponent 2012 of each RF module.

The strip of RF modules can be singulated into individual RF modules atblock 2058. In the process 2050, singulation is performed after forminga shielding layer over a portion of an RF module. FIG. 73F shows an RFmodule 2010A′ that includes a shielding layer over a portion of thepackaging substrate. The RF module 2010A′ of FIG. 73F can be similar tothe RF module 2010A′ of FIG. 72E except that the RF module 2010A′ ofFIG. 73F can include features resulting from removing a mask over theantenna and the RF module 2010A′ of FIG. 72E can include featuresresulting from laser removal of material of the shielding layer over theantenna.

Certain processes, such as the process 2050 of FIG. 73A and the process2060 of FIG. 74B, include forming a shielding layer prior to singulationof RF modules. In some other processes, the shielding layer can beformed after singulation of RF modules. In such processes, a conformalstructure can be formed along one or more edges of a singulated modulewhile forming a conductive layer over the singulated module. Theconformal structure can be included in a shielding structure around anRF component. The conformal structure implemented in place of wire bondsalong one or more sides of an RF component. FIGS. 74A, 75A, and 76A areexamples of processes that include forming a shielding layer aftersingulation of RF modules.

FIG. 74A is a flow diagram of an illustrative process 2060 that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment. Theprocess 2060 involves forming a shielding layer over a portion of an RFmodule by an additive method. In the process 2060, masking material canbe applied over selected portions of a plurality of RF modules of astrip, the RF modules can be singulated, a conductive layer can beformed over the RF modules and the masking material, and the maskingmaterial can be removed. FIGS. 74B to 74F illustrate an example module,strip of modules, or group of singulated modules corresponding tovarious stages of the process of FIG. 74A according to an embodiment.

At block 2061, RF modules that include an RF component and an integratedantenna are provided. The RF modules can include one or more conductivefeatures, such as wire bonds, disposed between the RF component and theantenna. The conductive features are RF isolation structures that areincluded in a shielding structure. FIG. 74B illustrates an example RFmodule 2010B that can be provided at block 2061. The RF module 2010B cangenerally correspond to the RF module 2010 of FIGS. 69 and 70 and the RFmodule 2010A of FIGS. 72B and 73B. The RF module 2010B includes wirebonds 2018 around fewer sides of the RF component 2012 than the RFmodules 2010 and 2010A. As illustrated in FIG. 74B, the wire bonds 2018are disposed between the RF component 2012 and the antenna 2014. Theillustrated wire bonds 2018 form a wall of wire bonds between the RFcomponent 2012 and the antenna 2014. As also illustrated, the RF module2010B of FIG. 74B includes an RF component 2012 that includes components2012A, 2012B, and 2012C.

A masking material can be provided over selected portions of RF modulesat block 2063. A strip of RF modules can be masked concurrently and/orsequentially at block 2063. The masking material can be relatively hightemperature tape. The masking material can be relatively low adhesiontape. The masking material can be applied over the antenna of each ofthe RF modules of a strip of RF modules. FIG. 74C shows a strip 2052 ofRF modules with masking material 2054 formed over a selected portion ofeach RF module of the strip 2052.

At block 2065, RF modules can be singulated. For instance, a jig saw canseparate individual RF modules from each other. The singulated RFmodules can be provided to a PVD ring. FIG. 74D shows a group ofsingulated RF modules 2066 prior to a shielding layer being formedthereon.

A conductive layer is formed over the singulated RF modules at block2067. The conductive layer can be in contact with wire bonds of asingulated RF module. The conductive layer can be formed by way ofsputtering. For example, the conductive layer can be formed inaccordance with any of the principles and advantages discussed withreference to block 2044 of the process 2040 as applied to singulatedmodules. FIG. 74E shows a group of singulated RF modules 2066′ with aconductive layer formed thereon. The conductive layer is substantiallyparallel to a package substrate of the RF module.

At block 2067, conformal conductive layers can also be formed alongedges of singulated RF modules. The conformal conductive layers can besubstantially orthogonal to and in contact with the conductive layerthat is substantially parallel to the package substrate. Accordingly,the shielding structure around the RF component can include the wirebonds 2018 around one side of the RF component, conformal conductivelayers around three sides of the RF component, and a shielding layerover the RF component. In other embodiments, wire bonds can be disposedalong two or three sides of the RF component and conformal conductivelayers can be disposed along the other side(s) of the RF component.Examples of such embodiments correspond to FIGS. 77E and 77F.

The masking material is removed at block 2069. The masking material canbe removed while the singulated RF modules are picked and placed into atray. The masking material can be removed in any suitable manner, suchas peeling the masking material or dissolving the masking material. Byremoving the masking material, portions of the conductive layer thatwere formed over the masking material are removed. Accordingly, theportion of the RF module that was covered by the masking material can beunshielded opposite the packaging substrate. Removing the maskingmaterial can leave features on the RF module. For example, a whiskerfeature and/or a relatively sharp step can be present from removing themasking material. FIG. 74F shows an RF module 2010B′ that includes ashielding layer over a portion of the packaging substrate.

FIG. 75A is a flow diagram of an illustrative process 2070 that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment. Theprocess 2070 involves forming a shielding layer over a portion of an RFmodule by a subtractive method. For instance, a selected portion of aconductive layer of a singulated RF module can be removed using a laserin the process 2070 instead of by masking in the process 2060 of FIG.74A. The process 2070 involves forming a conductive layer over thesingulated RF modules and then removing a selected portion of theconductive layer. FIGS. 75B to 75F illustrate an example module or groupof singulated modules corresponding to various stages of the process ofFIG. 75A according to an embodiment.

At block 2071, RF modules that include an RF component and an integratedantenna are provided. The RF modules can include one or more conductivefeatures, such as wire bonds, disposed between the RF component and theantenna. The conductive features are RF isolation structures that areincluded in a shielding structure. FIG. 75B illustrates an example RFmodule 2010B that can be proved at block 2071. The RF module 2010B cangenerally correspond to the RF module 2010 of FIGS. 69 and 70 and the RFmodule 2010A of FIGS. 72B and 72B. The RF module 2010B of FIG. 75B cancorrespond to the RF module 2010B of FIG. 74B. As illustrated, the RFmodule 2010B of FIG. 75B includes an RF component 2012 that includescomponents 2012A, 2012B, and 2012C. As also illustrated in FIG. 75B, thewire bonds 2018 are disposed between the RF component 2012 and theantenna 2014. The illustrated wire bonds 2018 form a wall of wire bondsbetween the RF component 2012 and the antenna 2014.

RF modules can be singulated at block 2073. For instance, a jig saw canseparate individual RF modules from each other. The singulated RFmodules can be provided to a PVD ring. FIG. 75B shows a group ofsingulated RF modules 2074 prior to a conductive layer being formedthereon. The RF modules 2074 can correspond to the RF modules 2066 ofFIG. 74D without masking material formed thereon.

A conductive layer is formed over the singulated RF modules at block2075. The conductive layer can be in contact with wire bonds of thesingulated RF module. The conductive layer can be formed by way ofsputtering. For example, the conductive layer can be formed inaccordance with any of the principles and advantages discussed withreference to block 2044 of the process 2040 as applied to singulatedmodules. FIG. 74C shows a group of singulated RF modules 2074′ with aconductive layer formed thereon. The conductive layer is substantiallyparallel to a package substrate of the RF module.

At block 2075, conformal conductive layers can also be formed alongedges of singulated RF modules. The conformal conductive layers can besubstantially orthogonal to and in contact with the conductive layerthat is substantially parallel to the package substrate. Accordingly,the shielding structure around the RF component can include the wirebonds 2018 around one side of the RF component, conformal conductivelayers around three sides of the RF component, and a shielding layerover the RF component. In other embodiments, wire bonds can be disposedalong two or three sides of the RF component and conformal conductivelayers can be disposed along the other side(s) of the RF component.Examples of such embodiments correspond to FIGS. 77E and 77F.

A selected portion of the conductive layer can be removed over anantenna of an RF module at block 2077. For instance, a laser can removethe conductive layer over the antenna of the RF module. Removing aportion of the conductive layer with a laser can leave features on theRF module. For example, burn features, such as a halo ring, can bepresent on an RF component after laser removal of a portion of theconductive layer. Laser removal can result in a rougher surface finishover the antenna relative to some other methods of forming a partiallyshielded RF module, such as methods that involve masking. The laserremoval can involve any of the principles and discussed with referenceto block 2046 of the process 2040 as applied to laser removal of aselected portion of a conductive layer of one or more singulated RFmodules. In the process 2070, laser removal is performed aftersingulation. By contrast, in the process 2040, laser removal of aselected portion of the conductive layer is performed prior tosingulation.

FIG. 74E shows a laser beam 2045 being applied to a singulated RFmodule. The laser can selectively remove the conductive layer over theRF module so that the RF module is left with an unshielded portion 2047and a shielded portion 2049. Accordingly, a shielding layer can bedisposed over the RF component and the antenna can be unshieldedopposite the package substrate. As such, the antenna can transmit and/orreceive RF signals without the shielding layer interfering.

At block 2077, singulated RF modules are picked and placed into a tray.FIG. 74F shows an RF module 2010B′ that includes a shielding layer overa portion of the packaging substrate that includes an RF component.

FIG. 76A is a flow diagram of an illustrative process 2080 that includesforming a shielding layer over a radio frequency component of a moduleand leaving an antenna unshielded according to an embodiment. Theprocess 2080 involves forming a shielding layer over a portion of an RFmodule by an additive method. Masking material can be applied over apanel of RF modules, the masking material can be cut and a portion ofthe masking material can be removed, a conductive layer can be formed,and the remaining masking material can be removed. FIGS. 76B to 76Iillustrate an example module, strip of modules, or group of singulatedmodules corresponding to various stages of the process of FIG. 76Aaccording to an embodiment.

At block 2081, RF modules that include an RF component and an integratedantenna are provided. The RF modules can include one or more conductivefeatures, such as wire bonds, disposed between the RF component and theantenna. The conductive features are RF isolation structures that areincluded in a shielding structure. FIG. 76B illustrates an example RFmodule 2010B that can be provided at block 2081. The RF module 2010B cangenerally correspond to the RF module 2010 of FIGS. 69 and 70 and the RFmodule 2010A of FIGS. 72B and 73B. The RF module 2010B of FIG. 76B cancorrespond to the RF module 2010B of FIG. 74B and the RF module 2010B ofFIG. 75B. As illustrated, the RF module 2010B of FIG. 76B includes an RFcomponent 2012 that includes components 2012A, 2012B, and 2012C. Asillustrated in FIG. 76B, the wire bonds 2018 are disposed between the RFcomponent 2010B and the antenna 2014. The illustrated wire bonds 2018form a wall of wire bonds between the RF component 2010B and the antenna2014.

A masking material can be provided over RF modules at block 2083. Themasking material can cover a strip of RF modules. The masking materialcan include any suitable features of the masking materials discussedherein. FIG. 76C shows a strip 2082 of RF modules with masking material2054 formed over the top surface of each of the RF modules of the strip2052. While the masking material is formed over the entire top surfaceof the RF modules in FIG. 76C, the masking material can be formed overany suitable portion of the top surface of the RF modules in some otherembodiments.

The masking material can be laser cut at block 2085. The maskingmaterial can be laser cut such that masking material can be over the RFmodules in any desired shape. Such desired shapes may be rectangular. Insome other embodiments, the desired shapes can be non-rectangular. Forinstance, curved features, circular features, elliptical features,non-rectangular polygonal features, or any combination thereof can belaser cut. FIG. 76D shows a strip 2082′ of RF modules with maskingmaterial 2054 that is laser cut.

At block 2087, a portion of the masking material can be removed.Accordingly, masking material can remain over a portion of an RF modulethat will be unshielded after the process 2080. For instance, themasking material can remain over the antenna of an RF module. FIG. 76Eshows a strip 2082″ of RF modules with masking material 2054 afterpartial removal.

RF modules can be singulated at block 2089. For instance, a jig saw canseparate individual RF modules from each other. The singulated RFmodules can be provided to a PVD ring. FIG. 76F shows a group ofsingulated RF modules 2090 prior to a conductive layer being formedthereon. FIG. 76G shows a singulated RF module with masking material2054 over a portion that will be unshielded after the process 2080. Thegroup of singulated RF modules 2090 can include a plurality of suchmodules. The RF modules 2090 can correspond to the RF modules 2066 ofFIG. 74D with a different pattern of masking material formed thereon.

A conductive layer is formed over the singulated RF modules at block2091. The conductive layer can be in contact with wire bonds of asingulated RF module. The conductive layer can be sputtered over the RFmodules. The conductive layer can be formed by way of PVD. For example,the conductive layer can be formed in accordance with any of theprinciples and advantages discussed with reference to forming theconductive layer in any of the methods discussed herein as suitable.FIG. 76H shows a group of singulated RF modules 2090′ with conductivelayers formed thereon. The conductive layer of each RF module issubstantially parallel to a package substrate of the RF module.

At block 2091, conformal conductive layers can also be formed alongedges of singulated RF modules. The conformal conductive layers can besubstantially orthogonal to and in contact with the conductive layerthat is substantially parallel to the package substrate. Accordingly,the shielding structure around the RF component can include the wirebonds 18 around one side of the RF component, conformal conductivelayers around three sides of the RF component, and a shielding layerover the RF component. In other embodiments, wire bonds can be disposedalong two or three sides of the RF component and conformal conductivelayers can be disposed along the other side(s) of the RF component.Examples of such embodiments correspond to FIGS. 77E and 77F.

The remaining masking material is removed at block 2093. The maskingmaterial can be removed in any suitable manner. By removing the maskingmaterial, portions of the conductive layer that were formed over themasking material are removed. Accordingly, the portion of the RF modulethat was covered by the masking material can be unshielded opposite thepackaging substrate. Removing the masking material can leave features onthe RF module. For example, a whisker feature and/or a relatively sharpstep can be present from removing the masking material. FIG. 76I shows aRF module 2010B′ with a top surface having a shielded portion and anunshielded portion. In the shielded portion, a shielding layer can beincluded in a shielding structure around an RF component. The antenna ofthe RF module can be unshielded opposite the package substrate in theunshielded portion.

At block 2095, singulated RF modules are picked and placed into a tray.

FIGS. 77A to 77F are schematic diagrams of examples of selectivelyshielded RF modules according to certain embodiments. Any of theprinciples and advantages discussed in connection with any of theseembodiments can be implemented in connection with any other of theseembodiments and/or any other embodiments discussed herein as suitable.Similar to FIG. 69, the RF modules of FIGS. 77A to 77F are shown in planview without a top shielding layer. The top shielding layer can beformed, for example, in accordance with any of the principles andadvantages discussed with reference to one or more of the processes ofFIG. 72A, FIG. 73A, FIG. 74A, FIG. 75A, or FIG. 76A. A shielding layercan be formed over the RF component of each of these RF modules and theantenna of each of these RF modules can be unshielded. Wire bonds ofeach of these modules can be in contact with the shielding layer suchthat both the wire bonds and the shielding layer are part of a shieldingstructure around an RF component. Although FIGS. 77A to 77F illustrateRF modules with a single antenna, any suitable principles and advantagesdiscussed herein can be applied to RF modules that include two or moreintegrated antennas.

FIGS. 77A to 77F illustrate various RF modules in accordance with theprinciples and advantages discussed herein. Each of these RF modules canbe selectively shielded in accordance with any suitable principles andadvantages discussed herein. FIGS. 77A to 77F illustrate that various RFcomponents can be implemented within a shielding structure, that variousshielding structures can be implemented, that antennas can have variousshapes and/or positions, or any suitable combination thereof. Forinstance, FIG. 77A shows an example of an RF component that includesthree different elements. Other RF components can alternatively oradditionally be implemented. FIGS. 77B, 77C, 77E, and 77F show thatshielding structures can include one, two, or three walls of wire bondsand conductive conformal structure(s) can be disposed along other sidesof the RF module to shield the RF component. Wire bonds can surround theRF component of the RF module in embodiments in which a shielding layeris formed prior to singulation of the RF modules. A conformal layer canbe disposed along at least one side the RF component of the RF module inembodiments in which a shielding layer is formed after singulation ofthe RF modules. The conformal structure can include any suitableconductive material. For example, the conductive conformal structure caninclude the same conductive material as the shielding layer in certainapplications. FIGS. 77D, 77E, and 77F show example antenna positions andshapes. Any of the RF modules discussed herein can include an antennathat is suitably positioned and of any suitable size and shape for aparticular application.

FIG. 77A is a schematic diagram of an example RF module 2010A accordingto an embodiment. The RF module 2010A of FIG. 77A shows that the RFcomponent 2012 of FIG. 69 can include a system on a chip 2012A, a frontend integrated circuit 2012B, and a crystal 2012C. The RF module 2010Aof FIG. 77A is an example of an RF module that can be provided in theprocess 2040 of FIG. 72A and/or in the process 2050 of FIG. 73A.

FIG. 77B is a schematic diagram of an example RF module 2010B accordingto an embodiment. The RF module 2010B of FIG. 77B is an example of an RFmodule that can be provided in the process 2060 of FIG. 74A, the process2070 of FIG. 75A, or the process 2080 of FIG. 76A. The RF module 2010Bof FIG. 77B is like the RF module 2010 of FIG. 69 except that wire bonds2018 are not surrounding the RF component 2012. In FIG. 77B, wire bonds2018 are disposed between the RF component 2012 and the antenna 2014.The remaining sides around the RF component in FIG. 77B are free fromwire bonds.

FIG. 77C shows the radio frequency module of FIG. 77B after a shieldinglayer 2032 and a conductive conformal structure 2098 are formed. Asillustrated in FIG. 77C, the conductive conformal structure 2098 can beformed along the outer edges of the module 2010B′. Such a conductiveconformal structure can be formed, for example, as described inconnection with the process 2060 of FIG. 74A, the process 2070 of FIG.75A, or the process 2080 of FIG. 76A. Accordingly, the shieldingstructure around the RF component 2012 in FIG. 77C includes wire bonds2018 disposed between the RF component 2012 and the antenna 2014 and aconductive conformal structure 2098 that includes three conformalconductive sides along edges of the RF module 2010B′. The wire bonds2018 and the conformal conductive surfaces can be in contact with theshielding layer 2032 disposed over the RF component 2012. The wire bonds2018 illustrated in FIGS. 77B and 77C are arranged as a wall. In someother instances, the conductive conformal structure can also be alongedges of the module 2010B′ around the antenna 2014. The shielding layercan be formed over the RF component 2012 and the antenna 2014 can beunshielded opposite the package substrate 2016.

FIG. 77D is a schematic diagram of an example RF module 2010C accordingto an embodiment. The RF module 2010C of FIG. 77D is like the RF module2010 of FIG. 69 except that an antenna 2014A surrounds the RF component2012 and the antenna 2014A has a different shape than the antenna 2014of FIG. 69. A shielding layer opposite the package substrate 2016 canshield the RF component 2012 and leave the antenna 2014A unshielded.

FIG. 77E is a schematic diagram of an example RF module 2010D accordingto an embodiment. The RF module 2010D of FIG. 77E is like the RF module2010 of FIG. 69 except both the shielding structure and the antenna aredifferent. In the RF module 2010D shown in FIG. 77E, the shieldingstructure includes three walls of wire bonds 2018 around the RFcomponent 2012. A conformal conductive layer can be formed along theside that is free from wire bonds. The conformal conductive layer and ashielding layer can be included in the shielding structure. The antenna2014B has a different position and shape than the antenna 2014 of FIG.69. The antenna 2014B shown in FIG. 77E is disposed around three of fourside of the RF component 2012. A shielding layer opposite the packagesubstrate 2016 can shield the RF component 2012 and leave the antenna2014B unshielded.

FIG. 77F is a schematic diagram of an example RF module 2010E accordingto an embodiment. The RF module 2010E of FIG. 77F is like the RF module2010 of FIG. 69 except the shielding structure and the antenna aredifferent. In the RF module 2010E shown in FIG. 77F, the shieldingstructure includes two walls of wire bonds 2018 around the RF component2012. A conformal conductive layer can be formed along the sides thatare free from wire bonds. The conformal conductive layer and a shieldinglayer can be included in the shielding structure. The antenna 2014C hasa different position and shape than the antenna 2014 of FIG. 69. Theantenna 2014C shown in FIG. 77F is disposed around two of four sides ofthe RF component 2012. A shielding layer opposite the package substrate2016 can shield the RF component 2012 and leave the antenna 2014Cunshielded.

Radio frequency modules can be selectively shielded such that ashielding layer opposite a package substrate covers any suitable portionof the radio frequency module. Such a shielding layer can have anysuitable pattern for a desired application. The pattern can be formed byablating conductive material, such as by laser scribing, and/or byremoving a mask to remove conductive material. The pattern can have anysuitable shape and/or size. For instance, such a pattern could cover anRF component shown in any of FIGS. 77A to 77F.

The unshielded portion of the radio frequency module can be exposed byablation. An ablation pattern can be any suitable pattern for a desiredapplication. For example, the ablation pattern can be a line, multiplelines such as multiple intersecting lines, a block, etc. Removingmasking material can alternatively perform a similar function asablating conductive material. Accordingly, an unshielded portion of aradio frequency module can have a shape of one or more lines and/or oneor more blocks in plan view. In some instances, an unshielded portion ofa radio frequency module can separate different shielded portions of theradio frequency module.

While the radio frequency modules of FIGS. 77A to 77F include anunshielded portion over an antenna, an unshielded portion can be overone or more other circuit elements (such as one or more matchingcircuits, one or more filters, one or more duplexers, the like, or anysuitable combination thereof) and/or between circuitry of differentportions of a radio frequency module. In certain applications, shieldingstructures can be segmented to keep one portion of a radio frequencymodule from interfering with another portion of the radio frequencymodule.

FIGS. 77G to 77J are diagrams of examples of selectively shielded RFmodules according to certain embodiments. Any of the principles andadvantages discussed in connection with any of these embodiments can beimplemented in connection with any other of these embodiments and/or anyother embodiments discussed herein as suitable. For instance, the topshielding layers of FIGS. 77G to 77J can be formed in accordance withany suitable principles and advantages discussed with reference to oneor more of FIG. 72A, FIG. 73A, FIG. 6A, FIG. 7A, or FIG. 76A.

FIG. 77G illustrates a shielded radio frequency module 2010F′ with anablation pattern leaving a portion of the radio frequency moduleunshielded according to an embodiment. The ablation pattern can extendover a top of the radio frequency module 2010F′ and also over opposingsides of the radio frequency module 2010F′. The ablation pattern can beformed by laser scribing, for example. Such laser scribing can removeconductive material and leave an unshielded portion 2047A that is freefrom the conductive material over a molding material. The laser scribingcan also remove some molding material (e.g., about 5 microns of moldingmaterial) in the unshielded portion 2047A. A width of the illustratedablation pattern can be in a range from about 40 to 150 microns, such asabout 100 microns, in certain applications.

As shown in FIG. 77G, unshielded portion 2047A separates a firstshielding structure from a second shielding structure. The firstshielding structure can provide shielding for an RF component. Theillustrated first shielding structure includes a top shielding layer2032A and three conformal sides. The three conformal sides can besubstantially orthogonal to the top shielding layer 2032A. The conformalsides can be connected to ground and provide a ground connection for thetop shielding layer 2032A. The first shielding structure can alsoinclude wire bonds on the fourth side adjacent to the unshielded portion2047A. Such wire bonds can be in contact with the top shielding layer2032A. Alternatively, a conductive conformal structure can be formedalong the fourth side and in contact with the top shielding layer 2032A.The second shielding structure can provide shielding for anotherelectronic component, such as another RF component. The illustratedsecond shielding structure includes a top shielding layer 2032B andthree conformal sides. The three conformal sides can be substantiallyorthogonal to the top shielding layer 2032B. The conformal sides can beconnected to ground and provide a ground connection for the topshielding layer 2032B. The second shielding structure can also includewire bonds on the fourth side adjacent to the unshielded portion 2047A.Such wire bonds can be in contact with the top shielding layer 2032B.Alternatively, a conductive conformal structure can be formed along thefourth side and in contact with the top shielding layer 2032B. Incertain applications, the first shielding structure and the secondshielding structure are both open on opposing sides of the unshieldedportion 2047A in a direction substantially orthogonal to the topshielding layers.

FIG. 77H illustrates a selectively shielded radio frequency module2010G′ according to an embodiment. In FIG. 77H, the unshielded portion2047A is wider than in FIG. 77G. The unshielded portion 2047A can have awidth in a range from about 300 microns to 700 microns, such as about500 microns. The unshielded portion 2047A can have any suitabledimension for a particular application.

FIG. 77I illustrates a selectively shielded radio frequency module2010H′ with an unshielded portion 2047A between two shielded portionsaccording to an embodiment. The radio frequency module 2010H′illustrates that two RF components of the same radio frequency modulecan shielded by different shielding structures. These RF components canbe any suitable RF components, such as RF components operating indifferent frequency bands (e.g., a high band and a low band). In theradio frequency module 2010H′, a first shielding structure providesshielding for a first RF component 2012-1 and a second shieldingstructure provides shielding for a second RF component 2012-2. Theshielding structures of the radio frequency module 2010H′ can reduceand/or eliminate inference between the first RF component 2012-1 and thesecond RF component 2012-2. The first RF component 2012-1 is positionedbetween a top shielding layer 2032A of the first shielding structure anda package substrate. The second RF component 2012-2 is positionedbetween a top shielding layer 2032B of the second shielding structureand the package substrate.

Conformal layers can form at least three sides of the first shieldingstructure of the radio frequency module 2010H′. Similarly, conformallayers can form at least three sides of the second shielding structureof the radio frequency module 2010H′. In certain applications, the firstshielding structure and the second shielding structure are both open onopposing sides of the unshielded portion 2047A in a directionsubstantially orthogonal to the top shielding layers. In some instances,one or more conductive features can be disposed between the first RFcomponent 2012-1 and the second RF component 2012-B. For example, thefirst shielding structure can include one or more wire bonds disposedbetween the RF component 2012-1 and the unshielded portion 2047A, inwhich the one or more wire bonds are in contact with the top shieldinglayer 2032A. Alternatively or additionally, the second shieldingstructure can include one or more wire bonds disposed between the RFcomponent 2012-2 and the unshielded portion 2047A, in which the one ormore wire bonds are in contact with the top shielding layer 2032B. Asanother example, the first shielding structure can include a conformalstructure disposed between the RF component 2012-1 and the unshieldedportion 2047A and/or the second shielding structure can include aconformal structure disposed between the RF component 2012-2 and theunshielded portion 2047A. Such a conformal structure can be formed inaccordance with any suitable principles and advantages discussed withreference to FIGS. 81A and 81B, for example. In some applications, laserscribing can remove conductive material within a through mold via sothat the bottom of the through mold via can correspond to the unshieldedportion 2047A.

FIG. 77J illustrates a selectively shielded radio frequency module2010I′ with an unshielded portion between shielded portions according toan embodiment. The radio frequency module 2010I′ illustrates anotherexample unshielded portion 2047B and example RF components 2012-1,2012-2A and 2012-2B, and 2012-3. The unshielded portion 2047B can beformed by ablating a conductive material over the module with a laserscribe, for example. As illustrated by FIG. 77J, the unshielded portion47B can segment a shielding structure into more than two separateshielding structures. The radio frequency module 2010I′ is an example inwhich 3 different components are packaged together (SoC 2012-1, frontend 2012-2A and SOC 2012-2, and crystal 2012-3) and are separated fromeach other by the unshielded portion 2047B. In some embodiments, one ormore conductive features in contact with a top shielding layer can be onone or both sides of some or all of the unshielded portion 2047B. Theone or more conductive features can include one or more wire bondsand/or a conformal structure.

Integrated antennas can be printed on a package substrate, for example,as discussed above. In certain embodiments, an integrated antenna can bea multi-layer antenna. For instance, a portion of an integrated antennacan be on a surface of a package substrate and another portion of theintegrated antenna can be implemented in another layer above or belowthe portion of the integrated antenna on the surface of the packagesubstrate. As an example, a portion of an integrated antenna can beprinted on a first side of a package substrate and another portion ofthe integrated antenna can be on a second side of the package substrate,in which the first side opposes the second side. As another example, ofan integrated antenna can be printed on a first side of a packagesubstrate and another portion of the integrated antenna can beimplemented over a molding layer of a radio frequency module. In someapplications, a multi-layer antenna can implement an antenna in asmaller foot print relative to similar a single layer antenna. This canreduce a footprint of the antenna and consequently reduce a footprint ofa radio frequency module that includes the antenna.

FIGS. 78A and 78B illustrate a radio frequency module 2100 that includesan integrated antenna implemented on opposing sides of a packagesubstrate 2016. The illustrated integrated antenna is multi-layerantenna. Any suitable principles and advantages of the RF module 2100can be implemented in combination with any of the other embodimentsdiscussed herein. The antenna can include traces on opposing sides ofthe package substrate. FIG. 78A is a top view of the radio frequencymodule 2100. FIG. 78B is a bottom view of the radio frequency module2100.

As shown in FIG. 78A, a first portion 2104A of an antenna can be on afirst side of a packaging substrate on which the RF component 2012 isalso disposed. The first portion 2104A can be implemented by aconductive trace. The first portion 2104A of the antenna can beelectrically connected to a second portion 2104B of the antenna by oneor more vias that extends through the packaging substrate 2016. Thefirst portion 2104A and the second portion 2104B can together implementthe antenna of the RF module 2100.

As shown in FIG. 78B, the second portion 2104B of the antenna can be onan opposite side of the packaging substrate 2016 than the first portion2104A. The second portion 2104A can be implemented by a conductivetrace. One or more pads can be disposed on the second portion 2104A ofthe antenna. As also shown in FIG. 78B, pads 2108A to 2108E can becontact with the second portion 2104A of the antenna. The pads 2108A to2108E can be exposed for providing connections between the antenna and asystem board on which the RF module 2100 is disposed. The pads 2108A to2108E can be soldered to the system board. One or more of the pads 2108Ato 2108E can serve as an anchor point to align the antenna of the RFmodule 2100 with the system board.

Referring back to FIG. 78A, the illustrated RF module 2100 includes amatching circuit 2106 that is implemented on the packaging substrate2016 external to the shielding structure. The illustrated matchingcircuit 2106 is electrically connected to the antenna. The matchingcircuit 2106 can provide impedance matching associated with the antenna.The matching circuit 2106 can include any suitable matching circuitelements, such as one or more capacitors and/or one or more inductors.As illustrated, the matching circuit 2106 includes three passive circuitelements 2106A, 2106B, and 2106C. The matching circuit 2106 can includemore or fewer circuit elements in other applications. For instance, amatching circuit can include two inductors in certain applications. Thematching circuit 2106 can have a relatively high activity factor.Accordingly, implementing the matching circuit 2106 external to theshielding structure can allow heat associated with the matching circuit2106 to dissipate outside of the shielding structure.

FIGS. 79A and 79B illustrate a radio frequency module 2110 that includesan integrated antenna partially implemented over molding material 2022.The illustrated integrated antenna is multi-layer antenna. Any suitableprinciples and advantages of the RF module 2110 can be implemented incombination with any of the other embodiments discussed herein. FIG. 79Ashows a partial view of the RF module 2110 with molding material omittedfor illustrative purposes. FIG. 79B shows a view of the RF module 2110with the molding material 2022. In FIGS. 79A and 79B, the antennaincludes a first portion 2114A and a second portion 2114B. The firstportion 2114A can be a conductive trace on the package substrate 2016.The second portion 2114B can be disposed over molding material 2022 ofthe RF module 2110. The second portion 2114B can include patternedconductive material over the molding material 2022. The second portion2114B can be implemented by the same material as the shielding layer2032 of a shielding structure of the RF module 2110. The second portion2114B can be formed during an operation during which the shielding layer2032 is formed. The second portion 2114B of the antenna and theshielding layer 2032 can be approximately the same distance from thepackaging substrate 2016. One or more wire bonds 2116 can electricallyconnect the first portion 2114A of the antenna with the second portionof the antenna 2114B.

It can be desirable to reduce the physical size of an RF module with anintegrated antenna. Certain antenna designs can reduce the physical sizeand/or footprint of such an RF module having an integrated antenna. FIG.80 illustrates an RF module 2120 with an integrated antenna 2124shielded from an RF component. Any suitable principles and advantages ofthe RF module 2120 can be implemented in combination with any of theother embodiments discussed herein. With the antenna 2124, the RF module2120 can have a length that is reduced about 15% to 20% relative to someother antenna designs. Accordingly, the RF module 2120 can have asmaller footprint that such other antenna designs.

Although the RF modules shown in FIGS. 77A to 77E include wire bondsdisposed between an RF component and an integrated antenna, otherconductive structures can provide shielding between the RF component andthe integrated antenna in certain embodiments. For example, a conductiveconformal structure can provide such shielding. Accordingly, aconductive conformal structure can be disposed between an RF componentand an integrated antenna in an RF module in accordance with anysuitable principles and advantages discussed herein.

Any of the processes of forming a shielding layer over a radio frequencycomponent of a module and leaving an antenna unshielded discussed hereincan be modified to form such a conformal layer. For example, a throughmold via can be formed through molding material of a molding structureof an RF module. Laser scribing can remove the molding material to formsuch a through mold via. Then a conductive layer can be formed over theRF module by sputtering or any other suitable manner. This can form aconductive layer over the molding material and within the through moldvia, including along a sidewall of the through mold via. The conductivelayer can then be removed over the integrated antenna such that theantenna of the RF module is unshielded over the packaging substrate.Such removal can be performed in accordance with any suitable principlesand advantages discussed herein, such as laser removal of conductivematerial over the antenna and/or removing masking material over theantenna. After removing the conductive layer over the antenna, aconductive conformal structure can remain within the through mold via.This conductive conformal structure can be in contact with the shieldinglayer over the RF component and be included in the shielding structurearound the RF component. Accordingly, this conductive conformalstructure can provide shielding between the RF component and the antennaof the RF module.

FIG. 81A illustrates an RF module 2130 with a through mold via 2132. Thethrough mold via 2132 can be formed by laser scribing, for example. Thethrough mold via 2132 can have one or more sloped sidewalls. Asillustrated, the through mold via 2132 is disposed between RF component2012 and the antenna 2014. The RF module 2130 includes a conductivelayer 2134 over molding material 2022. The conductive layer 2134 is alsoformed over the sloped sidewalls of the through mold via 2132. Thesloped sidewalls of the through mold via 2132 can enable a conductiveconformal structure between the RF component 2012 and the antenna 2014to be formed when the conductive layer is formed over the RF component2012. With sloped sidewalls, a conductive conformal structure can beformed with desirable step coverage between the antenna 2014 and RFcomponent 2012.

FIG. 81B illustrates an RF module 2130′ after the conductive layer 2134shown in FIG. 81A is removed over an antenna 2014. In the RF module2130′, a shielding structure around the RF component 2012 includes theshielding layer 2032 and a conductive conformal structure 2136 over asidewall of the through mold via 2132. The conductive conformalstructure 2136 is arranged to provide shielding between the RF component2012 and the antenna 2014. Other sides of the RF component 2012 can alsobe shielded by a conductive conformal structure. For instance, the RFcomponent 2012 of the RF module 2130′ can be surrounded by a conductiveconformal structure.

FIGS. 82A and 82B are diagrams of a shielded RF component on a carrierwith a printed antenna according to an embodiment. FIG. 82A is a topview and FIG. 82B is a side view. As shown in FIGS. 82A and 82B, acarrier 2140 can have an antenna 2014 printed thereon. The carrier 2140can be a package substrate, such as a laminate substrate. The carrier2140 can have fewer layers compared to the package substrates 2016discussed above. For example, in certain applications, the carrier 2140can include two layers and the package substrate 2016 can include fourlayers. An RF component 2012 can be shielded by a shielding structure2142, which can be a conformal shielding structure as illustrated. Apackaged component 2144 can be disposed on the carrier 2140 laterallyfrom the antenna 2014. Accordingly, the antenna 2014 can transmit and/orreceive signals without the shielding structure 2142 interfering. Thepackaged component 2144 can be disposed on the carrier 2140 such that aground pad on the carrier 2140 is electrically connected to theconformal shielding structure. The packaged component 2144 can include asystem in a package with a conformal shielding structure. The packagedcomponent 2144 can include molded system in a package with its ownpackage substrate.

Front end systems discussed herein can be implemented in accordance withany suitable principles and advantages of selective shielding discussedin this section. Any of the modules discussed in this section can beincluded in a wireless communication device, such as an IoT device ormobile phone (e.g., a smart phone). Any of the RF modules discussed inthis section can include or be included in a wireless personal areanetwork (WPAN) system. A WPAN system is an RF front end systemconfigured for processing RF signals associated with personal areanetworks (PANs). A WPAN system can be configured to transmit and receivesignals associated with one or more WPAN communication standards, suchas signals associated with one or more of Bluetooth, ZigBee, Z-Wave,Wireless USB, INSTEON, IrDA, or Body Area Network. Any of the RF modulesdiscussed in this section can include or be included in a wireless localarea network (WLAN) system. A WLAN system can process wireless localarea network signals, such as Wi-Fi signals.

Some of the embodiments described in this section have provided examplesin connection with RF components, front end system and/or wirelesscommunications devices. However, the principles and advantages of theembodiments of this section can be used for any other systems orapparatus that could benefit from any of the selective shieldingtechniques, shielding structures, integrated antennas, circuits, or anycombination thereof described herein. Although described in the contextof RF circuits, one or more features described in this section can beutilized in packaging applications involving non-RF components.Similarly, one or more features described in this section can also beutilized in packaging applications without electromagnetic isolationfunctionality. Moreover, while embodiments discussed in this sectioninclude an RF shielding structure and an antenna external to theshielding structure, other electronic components can be on a packagesubstrate of a module and external to a RF shielding structure on thepackage substrate instead of or in addition to an antenna. Theprinciples and advantages discussed in this section can be applied totwo or more shielding structures around electronic components on apackaging substrate and an antenna on the packaging substrate that isexternal to each of the two or more shielding structures. Any of theprinciples and advantages of the embodiments discussed in this sectioncan be used in any other systems or apparatus that could benefit fromany of the selective shielding features discussed herein.

Section VII—Shielded Radio Frequency Component with Integrated Antenna

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to a shielded radio frequency componentwith an integrated antenna. An antenna can be on a first side of amulti-layer substrate and a radio frequency component can be disposed ona second side of the multi-layer substrate such that a ground plane ofthe multi-layer substrate is positioned between the antenna and theradio frequency component. Conductive features can be disposed aroundthe radio frequency component and electrically connected to the groundplane. The conductive features and the ground plane can provideshielding for the radio frequency component. In certain embodiments, theconductive features can include bumps, such as solder bumps and/orcopper pillars. As indicated above, aspects of this section may becombined with other aspects of one or more other sections to furtherimprove the performance of front end systems and related devices,integrated circuits, modules, and methods in which they are employed.

There is a desire for a relatively low cost packaging technology toshield circuits to reduce radiated harmonics and also allow for anantenna unshielded from receiving and/or transmitting signals. Aspectsof this section relate to a shielded package with an integrated antenna.A laminated substrate can be fabricated in which an antenna is printedon the top layer and a ground plane for shielding is included in a layerunderneath the top layer. Other layers of the laminate substrate canimplement signal routing. An electronic component, such as a radiofrequency (RF) component, can be disposed along a bottom layer of thelaminate substrate. Bumps can be disposed around the electroniccomponent and electrically connected to the ground plane. The bumps canbe solder bumps in certain applications. The bumps can include copperpillars in various applications. The bumps can attach the module to acarrier or directly to a system board. The electronic component can besurrounded by bumps. For example, outside edges of the electroniccomponent can have ground bumps that are connected to the ground planeby way of vias. The ground bumps around the electronic component can beconnected to ground of a carrier or system board. Accordingly, ashielding structure with can be completed when the module is placed ontoa carrier or system board. The shielding structure can function as aFaraday cage around the electronic component. The shielding structurearound the electronic component can shield the electronic component fromsignals external to the shielding structure and/or shield circuitsoutside of the shielding structure from the electronic component.

One aspect of this section is a module that includes a multi-layersubstrate, an antenna, a radio frequency (RF) component, and conductivefeatures disposed around the RF component. The multi-layer substrate hasa first side and a second side opposite to the first side. Themulti-layer substrate includes a ground plane. The antenna is on thefirst side of the multi-layer substrate. The RF component is on thesecond side of the multi-layer substrate such that the ground plane ispositioned between the antenna and the RF component. The conductivefeatures are disposed around the RF component and electrically connectedto the ground plane. The conductive features and the ground planeconfigured to provide shielding for the RF component.

Another aspect of this section is an RF circuit assembly that includes alaminate substrate having a first side and a second side opposite thefirst side, a printed antenna on the first side of the laminatesubstrate, an RF component attached on the second side of the laminatesubstrate, and a plurality of bumps disposed around the RF component.The laminate substrate includes a ground plane that is positionedbetween the printed antenna and the RF component. The bumps form atleast a portion of an electrical connection to the ground plane tothereby form at least a portion of a shielding structure around the RFcomponent. The bumps can include solder bumps and/or copper pillars.

Another aspect of this section is system board assembly that includes alaminate substrate having a first side and a second side opposite to thefirst side, a printed antenna on the first side of the laminatesubstrate, an RF component attached on the second side of the laminatesubstrate, a plurality of bumps disposed around the RF component, and asystem board. The laminate substrate includes at least one layer forminga ground plane. The ground plane is positioned between the printedantenna and the RF component. The plurality of bumps is electricallyconnected to the ground plane. The system board includes ground padselectrically connected to ground plane by way of the plurality of bumpssuch that a shielding structure is formed around the RF component.

FIG. 83A shows a cross section of an antenna in a package system 2210according to an embodiment. The antenna in a package system 2210 is anexample of a radio frequency module. The antenna in a package system2210 includes an antenna integrated with and shielded from an RFcomponent. The antenna is unshielded from transmitting RF signals to andreceiving RF signals from remote to the system. Accordingly, the antennacan transmit and/or receive any suitable RF signal. The antenna cantransmit and/or receive RF signals for a system on a chip (SOC). Incertain embodiments, the antenna of the antenna in a package system 2210can be arranged to transmit and/or receive Bluetooth and/or ZigBeesignals.

The illustrated antenna in a package system 2210 includes a multi-layersubstrate 2212 that includes an antenna layer 2214, a ground plane 2216,an insulating layer 2220, and an other layer 2222. An RF component 2218is attached to the multi-layer substrate 2212 on a side opposite theantenna layer 2214. The ground plane 2216 is disposed between theantenna layer 2214 and the RF component 2218 such that the ground plane2216 provides shielding between the RF component 2218 and the antennalayer 2214. The antenna 2214 can be in communication with the RFcomponent 2218 by way of one or more wire bonds, by way of one or morevias extending through the substrate 2212 outside of the shieldingstructure, by way of magnetic coupling, or any suitable combinationthereof.

The multi-layer substrate 2212 can be a laminate substrate. Theinsulating layer 2220 can be disposed between the antenna layer 2214 andthe ground plane 2216. The insulating layer 2220 can include anysuitable dielectric material. The multi-layer substrate 2212 can includeone or more other layers 2222, which can implement signal routing and/orpassive components. Vias 2224 extending from the ground plane 2216 tothe bottom side of the multi-layer substrate 2212 shown in FIG. 83A canprovide ground connections at the bottom side of the multi-layersubstrate 2212. In some implementations, each of the vias 2224 can beimplemented by several vias through different insulating layersconnected to each other by metal in component layers disposed betweeninsulating layers.

The RF component 2218 can include any suitable circuitry configured toreceive and/or provide an RF signal. For instance, the RF component 2218can include a power amplifier, a low-noise amplifier, an RF switch, afilter, a matching network, or any combination thereof. An RF signal canhave a frequency in the range from about 30 kHz to 300 GHz. Inaccordance with certain communications standards, RF signal can be in arange from about 450 MHz to about 6 GHz, in a range from about 700 MHzto about 2.5 GHz, or in a range from about 2.4 GHz to about 2.5 GHz. Incertain implementations, the RF component 2218 can receive and/orprovide signals in accordance with a wireless personal area network(WPAN) standard, such as Bluetooth, ZigBee, Z-Wave, Wireless USB,INSTEON, IrDA, or Body Area Network. In some other implementations, theRF component and receive and/or provide signals in accordance with awireless local area network (WLAN) standard, such as Wi-Fi.

The RF component 2218 can be encapsulated in molding material 2226.Through mold vias 2228 can extend through the molding material 2226 tobumps 2229. The bumps 2229 can be any suitable conductive bumps, such assolder bumps, solder balls, copper pillars, or the like. The bumps 2229can facilitate mounting of the antenna in a package system 2210 onto asystem board. Bumps 2229 can be in physical contact with through moldvias 2228. Accordingly, the bumps 2229 can be electrically connected tothe ground plane 2216 by way of through mold vias 2228 and vias 2224 inthe multi-layer substrate 2212. While two bumps 2229, two through moldvias 2228, and two vias 2224 are illustrated in the cross section ofFIG. 83A, any suitable number of such elements can be included in theantenna in a package system 2210 to provide a suitable ground connectionand/or to provide suitable shielding around the RF component 2218. Forinstance, the bumps 2229 can extend along outer edges of the antenna ina package system 2210 to surround the RF component 2218 in plan view.Corresponding through mold vias 2228 and vias 2224 can be implementedwith such bumps 2229.

FIG. 83B shows a cross section of an antenna in a package system 2210′according to an embodiment. The antenna in a package system 2210′ isanother example of a radio frequency module. The antenna in a packagesystem 2210′ of FIG. 83B is similar the antenna in a package system 2210of FIG. 83A except that the RF component 2218 is unencapsulated in theantenna in a package system 2210′ and the bumps 2229 are in physicalcontact with vias 2224 in the multi-layer substrate 2212. In someapplications, the antenna in a package system 2210′ can be mounted ontoa carrier.

FIG. 84 shows a cross section of an antenna in a package system 2230with bumps providing standoff according to an embodiment. FIG. 84 showsthat after reflow bumps 2232 can extend farther from a module than asolder resist 2234. This can enable the bumps 2232 to provide standoffbetween an RF component and a system board or other substrate on whichan antenna in a package system 2230 is disposed. Any suitable featuresshown in FIG. 84 can be implemented in connection with any of theantenna in a package systems discussed herein.

FIGS. 85A to 85C illustrate example system board assemblies. Anysuitable principles and advantages associated with these system boardassemblies can be implemented with any of the antenna in a packagesystems and/or any of the RF modules discussed herein. FIG. 85Aillustrates a system board assembly 2240 with an antenna in a packagesystem 2210 and other component(s) 2242 disposed on a system board 2244according to an embodiment. The system board 2244 can be any suitableapplication board, such as a phone board for a mobile phone. Bumps 2229of the antenna in a package system 2210 can be in physical contact withone or more ground connections of the system board 2244. Accordingly, ashielding structure can at least partly surround the RF component 2218of the antenna in a package system 2210 in three dimensions. Theshielding structure can provide shielding between the RF component 2218and the antenna layer 2214 of the antenna in a package system 2210. Theshielding structure can provide shielding between the RF component 2218and one or more other components 2242 disposed on the system board 2244.Accordingly, the RF component 2218 can be shielded from radiationemitted by the one or more other components 2242. At the same time, theother component(s) 2242 can be shielded from radiation emitted from theRF component 2218. The other component(s) 2242 can include any othercircuitry on the system board 2244, such as other RF circuitry, abaseband processor, memory, the like, or any suitable combinationthereof.

FIG. 85B illustrates cross section of a system board assembly 2240 withan antenna in a package module and another component 2242 disposed on asystem board 2244 according to an embodiment. As illustrated, the systemboard 2244 includes ground pads 2241A in contact with bumps 2229. InFIG. 85B, inner bumps 2243 are surrounded by a shielding structure thatincludes bumps 2229. The inner bumps 2243 can provide electricalconnections between circuitry of the RF component 2218 and the systemboard 2244. Pads 2241B on the system board 2244 can be electricallyconnected to the RF component 2218 by way of respective bumps 2243, vias2228′, routing metal 2247, and vias 2245. The antenna of the antennalayer 2214 can be electrically connected to a pad 2241C of the systemboard 2244. As illustrated, a wire bond 2246 electrically connects theantenna to the pad 2241C. The system board 2244 can provide signalrouting between the antenna and the RF component 2218 and/or the othercomponents 2242.

FIG. 85C illustrates cross section of a system board assembly 2240′ withan antenna in a package module and another component 2242 disposed on asystem board 2244 according to an embodiment. The system board assembly2240′ is like the system board assembly 2240 of FIG. 85B except that adifferent antenna in a package system is implemented. In the systemboard assembly 2240′, pads 2241B on the system board 2244 can beelectrically connected to the RF component 2218 by way of respectivebumps 2243, vias 2245, and routing metal 2247.

FIG. 86 is a cross sectional view of an antenna in a package system 2248according to an embodiment. The illustrated antenna in a package system2248 includes several components of the antenna in a package systems ofFIGS. 83A and 83B. In FIG. 86, more details regarding the layers 2222are illustrated. In the illustrated antenna in a package system 2248,the layers 2222 can implement signal routing. As shown in FIG. 86, theRF component 2218 and the molding material 2226 can be thicker in theillustrated vertical dimension than the multi-layer substrate 2212.

FIGS. 87A and 87B are example cross sectional views of layers radiofrequency circuit assemblies 2250 and 2250′, respectively, withintegrated antennas according to certain embodiments. These figuresgenerally illustrate the layers of the radio frequency circuitassemblies. Details of some examples of the illustrated layers of FIGS.87A and 87B are provided in connection with FIGS. 88A to 89D.

In FIG. 87A, the illustrated radio frequency circuit assembly 2250includes an antenna layer 2214, a ground plane 2216, an insulating layer2220 disposed between the antenna layer 2214 and the ground plane 2216,a component layer 2251, routing layers 2252, 2255, 2257, and insulatinglayers 2253, 2254, 2256, and 2258. The routing layers 2252, 2255, 2257,the insulating layers 2220, 2253, 2254, 2256, and 2258, and the groundplane 2216 can be included in a laminated substrate. The antenna layer2214 can also be considered part of the laminated substrate. Thecomponent layer 2251 can be integrated with the laminated substrate. Thecomponent layer 2251 can include any of the RF components discussedherein, such as the RF component 2218. The component layer 2251 caninclude a semiconductor die that includes RF circuits.

Each of the routing layers can have insulating layers on opposing sidesto insulate the routing layers from others routing layers and/or otherlayers, such as the ground plane 2216 or the component layer 2251. Asillustrated, an insulating layer 2253 is disposed between the groundplane 2216 and the routing layer 2252 closest to the ground plane 2216.As also shown in FIG. 87A, an insulating layer 2258 is disposed betweenthe component layer 2251 and the routing layer 2257 closest to thecomponent layer 2251. The insulating layers can be formed of, forexample, any suitable dielectric material. The routing layers canimplement metal routing. Vias (not illustrated in FIG. 87A) extendingthrough an insulating layer can provide connections between metal inlayers on opposing sides of the insulating layer.

Any suitable number of routing layers can be included in a radiofrequency circuit assembly. For instance, the radio frequency circuitassembly 2250′ of FIG. 87B includes one routing layer 2252. As anotherexample, the radio frequency circuit assembly 2250 of FIG. 87A includesthree routing layers 2252, 2255, 2257. Relatively more routing layerscan be implemented to handle an increasing amount of signal routingbetween circuitry of the component layer 2251. Alternatively oradditionally, relatively more routing layers can be implemented tohandle an increasing amount of signal routing between circuitry of thecomponent layer 2251 and circuitry external to a radio frequency circuitassembly 2250 and/or 2250′. Signal routing can be shielded by ashielding structure that includes the ground plane 2216 and vias throughthe insulating layers of the radio frequency circuit assembly 2250and/or 2250′ connected with ground solder bumps and disposed around anRF component of the component layer 2251. Such vias can be electricallyconnected to conductive features, such as bumps, disposed around the RFcomponent in the component layer 2251. Passive components, such as oneor more spiral inductors, can be implemented in one or more of therouting layers. One or more passive components in routing layer(s) canbe included in a matching network associated with radio frequencycircuitry of the component layer 2251.

The antenna layer 2214 of any of the antenna in a package systemsdiscussed herein can include any suitable printed antenna. A printedantenna can be formed from one or more conductive traces on a substrate.The one or more conductive traces can be formed by etching a metalpattern on the substrate. A printed antenna can be a microstrip antenna.Printed antennas can be manufactured relatively inexpensively andcompactly due to, for example, their 3-dimensional physical geometries.Printed antennas can have a relatively high mechanical durability.

FIGS. 88A and 88B illustrate example printed antennas of radio frequencycircuit assemblies according to certain embodiments. These figuresillustrate examples of a top view of a radio frequency circuit assembly,such as the radio frequency circuit assembly 2250 and/or 2250′. Theantenna 2260 can be any suitable shape. For instance, the antenna 2260can be U-shaped as shown in FIG. 88A. The antenna 2260 in FIG. 88A canbe a folded quarter wave antenna. As another example, the antenna 2260′can be a meandering shape as shown in FIG. 88B. The antenna can be coilshaped in certain implementations. The antenna can be a loop antenna insome implementations. The antenna of the antenna layer 2214 and/or 2214′can serve as an antenna for a system on a chip. The antenna can transmitand/or receive any suitable wireless communication signal. Such antennascan be configured to transmit and/or receive Bluetooth and/or ZigBeesignals, for example. The antenna of the antenna layer can be incommunication with transmit and/or receive circuitry by way of one ormore wire bonds, by way of one or more vias extending through asubstrate on which the antenna is disposed (e.g., outside of theshielding structure), by way of magnetic coupling, or any suitablecombination thereof. The antenna of the antenna layer can be incommunication with an RF component shielded from an antenna by ashielding structure by way of one or more wire bonds, by way of one ormore vias extending through a substrate on which the antenna is disposed(e.g., outside of the shielding structure), by way of magnetic coupling,or any suitable combination thereof.

FIGS. 89A to 89D illustrate example component layers of radio frequencycircuit assemblies according to certain embodiments. These figuresinclude schematic views of a bottom view of a radio frequency circuitassembly, such as the radio frequency circuit assembly 2250 and/or2250′.

As illustrated in FIGS. 89A to 89D, ground bumps 2229 can surround an RFcomponent and form a portion of a shielding structure around the RFcomponent. The ground bumps 2229 can be disposed along each edge of thecomponent layer 2251. The ground bumps 2229 can be soldered or otherwiseconnected to a ground connection of a carrier assembly such that theground plane 2216, the bumps 2229, and ground of the carrier assemblytogether provide three-dimensional shielding of the RF component. Thecarrier assembly can be implemented by ethylvinylbenzene (EVB) oranother laminate, for example.

As illustrated, the ground bumps 2229 surround signal routing bumps2271. The signal routing bumps 2271 can provide at least a portion of aconnection between circuitry of the component layer 2251 with metalrouting in a routing layer that is disposed between the component layer2251 and the ground plane 2216. Alternatively or additionally, thesignal routing bumps 2271 can provide at least a portion of anelectrical connection between circuitry of the RF component 2218 and asystem board on which an antenna in a package system is disposed.

The example component layers of FIGS. 89A to 89D illustrate variouselectronic components that can be shielded from the antenna of theantenna layer 2214 by the ground plane 2216. Each of these figuresillustrates circuitry that can be included within a shielding structure.Other circuitry and/or components can alternatively or additionally beincluded within such a shielding structure. For instance, one or more ofa crystal, a front end integrated circuit, or a system on a chip can beincluded within the shielding structure. As one example, a crystal, afront end integrated circuit, and a system on a chip can be implementedwithin the shielding structure and shielded from an integrated antennaby the shielding structure.

FIG. 89A illustrates a component layer 2251 that includes an RFcomponent 2218 connected to signal routing bumps 2271. Some example RFcomponents are illustrated in FIGS. 89B to 89D. FIG. 89B illustrates acomponent layer 2251′ that includes a low noise amplifier (LNA) 2272 anda matching network 2273. FIG. 89C illustrates a component layer 2251″that includes a power amplifier 2274 and a matching network 2275. FIG.89D illustrates a component layer 2251′″ that includes an LNA 2272, apower amplifier 2274, and matching networks 2273 and 2275. The circuitsillustrated in FIGS. 89A to 89D are connected to signal routing bumps2271 and are surrounded by the ground bumps 2229 in a respectivecomponent layer. In some other implementations, the matching network2273 and/or the matching network 2275 can include one or more passivecomponent (e.g., one or more resistors, one or more capacitors, and/orone or more inductors implemented in a routing layer disposed between acomponent layer and a ground plane.

Front end systems discussed herein can be implemented in accordance withany suitable principles and advantages of a shielded radio frequencycomponent with an integrated antenna discussed in this section. Packagedmodules discussed in this section can be relatively low cost laminatebased front end modules that combine low noise amplifiers with powernoise amplifiers and/or RF switches in certain implementations. Somesuch packaged modules can be multi-chip modules. The integrated antennaof such RF modules can be implemented in accordance with any of theprinciples and advantages discussed herein. These RF front end modulescan be antenna in a package systems. The integrated antenna can beimplemented in an antenna layer on a first side of a substrate that isshielded from the circuits of the RF front end on a second side of thesubstrate at least partly by a ground plane implemented in a layer ofthe substrate.

Any of the embodiments discussed in this section can be included in awireless communication device, such as an IoT device or mobile phone(e.g., a smart phone). Any of the embodiments discussed in this sectioncan include or be included in a wireless personal area network (WPAN)system. A WPAN system is an RF front end system configured forprocessing RF signals associated with personal area networks (PANs). AWPAN system can be configured to transmit and receive signals associatedwith one or more WPAN communication standards, such as signalsassociated with one or more of Bluetooth, ZigBee, Z-Wave, Wireless USB,INSTEON, IrDA, or Body Area Network. Any of the embodiments discussed inthis section can include or be included in a wireless local area network(WLAN) system. A WLAN system can process wireless local area networksignals, such as Wi-Fi signals.

Some of the embodiments described in this section have provided examplesin connection with RF components, front end modules and/or wirelesscommunications devices. However, the principles and advantages of theembodiments can be used for any other systems or apparatus that couldbenefit from any of the shielding associated with an integrated antennadescribed in this section. Although described in the context of RFcircuits, one or more features described herein can also be utilized inpackaging applications involving non-RF components. Similarly, one ormore features described herein can also be utilized in packagingapplications without the electromagnetic isolation functionality. Any ofthe principles and advantages of the embodiments discussed can be usedin any other systems or apparatus that could benefit from the antennasand/or the shielding structures discussed herein. Any of the principlesand advantages of the embodiments discussed in this section can be usedin any other systems or apparatus that could benefit from any of thetechnology described in this section.

Section VIII—Packaged Module with Stacked Components

In accordance with some embodiments of this disclosure, this section ofthe present disclosure relates to a packaged module with stackedcomponents. A packaged module can be a system-in-a package (SiP). TheSiP can include integrated circuits (ICs) including system-on-a-chip(SoC) and discrete components using vertical integration technologies tointegrate at least some of the components. A feature of the SiP is arelatively small package size in length (x dimension) and width (ydimension). This section provides a number of options to stack the SoC,crystal, surface mount components (SMTs), and a front-end integratedcircuit (FEIC) on a substrate. As the crystal is generally smaller thanthe SoC, the footprint of the crystal and crystal routing caneffectively be removed from the x and y dimensions of the SiP. Inaddition to reducing package size, other advantages that can be realizedinclude decreased crystal trace parasitic capacitance and/or reducedcoupling between the crystal routing traces and other sensitive paths onthe substrate. As indicated above, aspects of this section may becombined with other aspects of one or more other sections to furtherimprove the performance of front end systems and related devices,integrated circuits, modules, and methods in which they are employed.

Any of the SiPs, multi-chip modules (MCMs), and other packaged devicesor other components described in this section, including those havingvertically integrated/stacked configurations can be configured toimplement wireless RF transceiver and/or front end functionality. Forinstance, such devices can be configured to support one or more wirelesslocal area network (WLAN) standards such as Wi-Fi or Bluetooth (e.g.,compliant with one or more of the IEEE 802.11 family of standards),and/or one or more cellular technologies, such as Long Term Evolution(LTE), Global System for Mobile Communications (GSM), Wideband CodeDivision Multiple Access (WCDMA), and/or Enhanced Data Rates for GSMEvolution (EDGE).

In the SiPs of this section, a substrate can provide theinterconnections to form at least a portion of an electric circuit. Inan embodiment, a printed circuit board (PCB) or some other board canmechanically support and electrically connect electrical componentsusing conductive tracks, pads, and/or other features laminated onto asubstrate. In an embodiment, a SiP includes a number of ICs mounted on asubstrate and enclosed in a single package. The integrated circuits inthe SiP can be internally connected by fine wires that are bonded to thepackage. In an embodiment, SoC includes an IC that integrates one ormore components of an electronic system into a single substrate. In anembodiment, a multi-chip module (MCM) includes an electronic assemblythat includes multiple integrated circuits (ICs), semiconductor dies,and/or other discrete components integrated onto a unifying substrate.

FIG. 90A illustrates an example top view of a multi-chip module (MCM)2300 including a system-in-a-chip (SoC) 2302, a front-end integratedcircuit (FEIC) 2304, a crystal 2308, crystal load capacitors 2306, andother surface mount devices on a substrate 2312, which includes tracesand other interconnect devices to electrically connect the SMTcomponents and components 2302, 2304, 2306, 2308. The crystal 2308 andthe crystal load capacitors 2306 can form at least a portion of acrystal oscillator.

FIG. 90A further illustrates relatively long crystal traces 2310providing electrical communication between the crystal 2308 and the SoC2302. Due to the horizontal layout of the MCM 2300, the crystal traces2310 can be susceptible to introducing parasitic capacitance to the MCMcircuitry and increase coupling between the crystal routing traces 2310and other sensitive paths on the substrate 2312. The parasiticcapacitance can adversely affect the startup margin. The startup marginis the ability of the crystal to start oscillating at power up, and isdefined as R/ESR, where R is the maximum series resistance added to thecrystal path that allows oscillation and ESR is the equivalent seriesresistance of the crystal.

FIG. 90B is an example block diagram of the MCM 2300 and illustrates theMCM 2300 including the SoC 2302, which includes at least amicrocontroller (or microprocessor) and a radio. The illustrated MCM2300 further includes the FEIC 2304 which includes at least one of apower amplifier (PA), a low noise amplifier (LNA), and a radio frequencyswitch, such as double pole double throw switch. The illustrated MCM2300 further includes the crystal 2308 and crystal traces 2310.

FIG. 90C is an example side view of the MCM 2300 and illustrates thehorizontal layout of the SoC 2302, the FEIC 2304, the load capacitors2306, and the crystal 2308 on the substrate 2312.

A multi-chip module (MCM) can include an electronic assembly, such as apackage with a number of conductor terminals such as “pins”, wheremultiple integrated circuits (ICs), semiconductor dies and/or otherdiscrete components are integrated, typically onto a unifying substrate,so that in use it is treated as if it were a single component as thougha larger IC.

A system on a chip or system on chip (SoC) is an integrated circuit (IC)that integrates all components of a computer or other electronic systeminto a single chip. It may include digital, analog, mixed-signal, and/orradio-frequency functions on a single chip substrate.

A front-end integrated circuit (FEIC) or a front-end module (FEM) caninclude at least one of a power amplifier (PA), a low noise amplifier(LNA), and radio frequency switch, such as a double pole double throwswitch. The RF front end can include the circuitry between the antennaup to and including the mixer stage, such that the RF front-end includesthe components in the receiver that process the signal at the originalincoming radio frequency (RF), before it is converted to a lowerintermediate frequency (IF).

RF front end circuitry can use a local oscillator (LO) that generates aradio frequency signal at an offset from the incoming signal, which ismixed with the incoming signal. The LO can include a crystal oscillator,which includes an electronic oscillator circuit that uses the mechanicalresonance of a vibrating crystal of piezoelectric material to create anelectrical signal with a precise frequency.

A crystal oscillator is an electronic oscillator circuit that uses apiezoelectric resonator, such as a crystal, as its frequency-determiningelement. Crystal is a common term used in electronics for thefrequency-determining component, a wafer of quartz crystal or ceramicwith electrodes connected to it. The frequency determining component canbe referred to as a piezoelectric resonator.

Load capacitors are associated with the crystal and can function toapproximately match the total capacitance seen from the crystal lookinginto the crystal oscillator circuit, in order to operate the crystal ata desired frequency.

Crystals can include separate components for use in crystal oscillatorcircuits. The crystal can be packaged with the load capacitors. In someinstances, a crystal oscillator includes the crystal, the loadcapacitors, and an amplifier incorporated in a single package with thecrystal oscillator circuit.

A system-in-package or system-in-a-package (SiP) includes one or moreintegrated circuits enclosed in a single module or package. Diescontaining integrated circuits may be stacked vertically on a substrate.They can be internally connected by wire bonds that are bonded to thepackage. Alternatively, with a flip chip technology, bump (e.g., solderbumps) can be used to make electrical connections among stacked chips.

SiP dies can be stacked vertically or tiled horizontally, unlikeslightly less dense multi-chip modules, which place dies horizontally ona carrier. An SiP can connect the dies with standard off-chip wire bondsor bumps, unlike slightly denser three-dimensional integrated circuitswhich connect stacked silicon dies with conductors running through thedie.

Novel 3-D packaging techniques are disclosed herein for stacking chipdies and/or passive components, such as capacitors and resistors, into acompact area on a substrate. Novel embodiments to stack a SoC and acrystal are disclosed herein. Further, various novel stacking assembliesand novel stacking configurations are disclosed within. FIGS. 91-106illustrate various embodiments of a system-in-a-package. Any of thesesystems-in-a-package can be used in a wireless communication device.

FIG. 91 illustrates an embodiment of a system-in-a-package (SiP) 2400for use in a wireless device. SiP 2400 includes a SoC 2402, a FEIC 2404,a packaging substrate 2412, a crystal 2408, one or more load capacitors2406, a routing substrate or interposer 2414, one or more ground bondwires 2420, and one or more wire bonds 2418 that electrically connectthe crystal 2408 to the SoC 2402. In an embodiment, the one or more wirebonds 2418 electrically connect the crystal 2408 to a crystal oscillatorcircuit on the SoC 2402.

FIG. 91 shows the one or more load capacitors 2406 as being external tothe SoC 2402. In some other embodiments, the SoC 2402 includes the oneor more load capacitors 2406.

The illustrated SoC 2402 is epoxied to the substrate 2412 and wirebonded to the substrate 2412. The routing substrate 2414 is stacked ontop of the SoC 2402. The crystal 2408 and its load capacitors 2406 canthen be soldered on the top of the routing substrate 2414.

The routing substrate 2414 holds the crystal 2408 and the capacitors2406 and routes signals to the crystal 2408. In an embodiment, therouting substrate 2414 includes a single layer or a multi-layerlaminate.

In an embodiment, the one or more ground bond wires 2420 are incommunication with a ground node, such as a ground plane, a grounded viaor the like, on the substrate 2412 and the routing substrate 2414 inturn routes the ground signal to the crystal 2408. In an embodiment, theone or more wire bonds 2418 are in communication with devices, such as acrystal oscillator or the like, on the SoC 2402 and the routingsubstrate 2414, which in turn, routes the signals to the crystal 2408.

Stacking the crystal 2408 and the capacitors 2406 permits the substrate2412 be smaller (have a smaller footprint) than the substrate 2312 andprovides the same or similar functionality. An advantage of stacking thecrystal 2408 and the capacitors 2406 is not only space savings, but alsothe length of at least one trace between the crystal 2408 and the SoC2402 can be significantly reduced. It can be desirable to have as shorta trace as possible between a crystal and a SoC to reduce parasiticcapacitance of the trace. By stacking the crystal 2408 over the SoC2402, the trace is all but eliminated and the opportunity for parasiticcapacitance to develop is greatly reduced. In an embodiment, the signalsto/from the crystal 2408 are routed from the SoC 2402 directly to therouting substrate 2414 by way of the one or more wire bonds 2418.Another benefit of reducing the traces in communication with the crystal2508 is a reduced opportunity of coupling between the crystal path andother sensitive paths on the substrate 2412, such as RF traces that arein communication with the FEIC 2404, for example.

FIG. 92 illustrates an embodiment of a system-in-a-package 2500 for usein a wireless device. SiP 2500 includes a SoC 2502, a FEIC 2504, apackaging substrate 2512, a crystal 2508, one or more load capacitors2506, a routing substrate 2514, one or more ground bond wires 2520, andone or more wire bonds 2518 that electrically connect the crystal 2508to the SoC 2502. In an embodiment, the one or more wire bonds 2518electrically connect the crystal 2508 to a crystal oscillator on the SoC2502.

The SiP 2500 is similar to the SiP 2400 except that the SoC 2502includes a flip chip package. The SoC 2502 is soldered to the substrate2512. Similar to the stacking arrangement of the SiP 2400, the routingsubstrate 2514 is stacked on top of the SoC 2502 and the crystal 2508and its load capacitors 2506 are then soldered on the top of the routingsubstrate 2514. In an embodiment, the SoC 2502 is immediately adjacentto the substrate 2512 and to the routing substrate 2514; and the crystal2508 is immediately adjacent to the routing substrate 2514.Advantageously, the SiP 2500 can provides space savings, reduced lengthof traces in the crystal path, decreased parasitic capacitance,decreased signal coupling, or any combination thereof.

FIG. 93 illustrates an embodiment of a system-in-a-package 2600 for usein a wireless device. SiP 2600 includes a SoC 2602, a FEIC 2604, apackaging substrate 2612, a crystal 2608, one or more load capacitors2606, one or more wire bonds 2620 that electrically connect signals fromthe SoC 2602 to traces on the substrate 2612, and one or more wire bonds2618 that electrically connect signals associated with the crystal 2608to signals associated with the SoC 2602 by way of routing traces on thesubstrate 2612. In the SiP 2600, the crystal 2608 is over the substrate2612 and the SoC 2602 is stacked directly over the crystal 2608, withouta routing substrate between the SoC 2602 and the crystal 2608. In anembodiment, the crystal 2608 is immediately adjacent to the SoC 2602 andthe substrate 2612. In an embodiment, the footprint of the SoC 2602 islarger than the footprint of the crystal 2608, which creates an overhangvolume that is bounded by the sides of the crystal 2608, the portion ofthe SoC 2602 that extends beyond crystal 2608, and the portion of thesubstrate 2612 that is within the footprint of the SoC 2602 and notcovered by the crystal 2608.

In an embodiment, the load capacitors 2606 and/or the FEIC 2604 areplaced outside of the SoC footprint. In another embodiment, the loadcapacitors 2606 and/or the FEIC 2604 are placed between the SoC 2602 andthe crystal 2608 within the SoC footprint. In another embodiment, theload capacitors 2606 and/or the FEIC 2604 are placed within the overhangvolume.

There are several factors to consider when utilizing the overhangvolume. Factors to consider include, but are not limited to, thethickness of the SoC, bond wire types, an amount of pressure used tobond the bond wire to the SoC without cracking the SoC, an amount ofoverhang that can be supported, and the like.

FIG. 94A illustrates another embodiment of a system-in-a-package 2700for use in a wireless device. SiP 500 includes a SoC 2702, a FEIC 2704,a packaging substrate 2712, a crystal 2708 a, and one or more loadcapacitors 2706 a. The crystal 2708 a includes a flip chip or controlledcollapse chip connection (C4) package and is stacked over the SoC 2702,which is over the substrate 2712. In an embodiment, the FEIC 2704 andthe load capacitors 2706 a are placed on the substrate 2712 beside theSoC 2702.

In an embodiment, the crystal 2708 is soldered to the SoC 2702 throughthe solder bumps of the flip chip package to matching pads on the SoC2702. In an embodiment, there are no wire bonds between the crystal 2708and the SoC 2702. In an embodiment, when the crystal 2708 is soldered tothe SoC 2702, the crystal 2708 and the SoC 2702 are in electricalcommunication, such that a length of a trace between the crystal 2708and a crystal oscillator on the SoC 2702 is short.

FIG. 94B illustrates another embodiment of a surface mount crystal 2708b for use in a system-in-a-package. In this embodiment, the crystal 2708b is flipped on its back, such that the crystal bond pads are up. Thetop of the package of the crystal 2708 b is bonded or epoxied to thelayer below. In an embodiment, the layer below the crystal 2708 bincludes a SoC. In another embodiment, the layer below the crystal 2708b includes the substrate. Bond wires from the bond pads of the crystal2708 b bond down to connect ground, crystal oscillator connections, loadcaps, the like, or any combination thereof.

FIG. 94C illustrates another embodiment of a surface mount crystal 2708c and at least one surface mount load capacitor 2706 c for use in asystem-in-a-package. In this embodiment, the crystal 2708 c is flippedon its back, such that the crystal bond pads are up. The top of thepackage of the crystal 2708 c is bonded or epoxied to the layer below.In an embodiment, the layer below the crystal 2708 c includes a SoC. Inanother embodiment, the layer below the crystal 2708 c includes thesubstrate. The surface mount load capacitor 2706 c is bonded directlyonto the crystal bond pads of the flipped crystal 2708 c. Bond wiresfrom the bond pads of the surface mount load capacitor 2706 c bond downto connect ground, crystal oscillator connections, the like, or anysuitable combination thereof.

FIG. 94D illustrates another embodiment of a surface mount crystal 2708d and at least one surface mount load capacitor 2706 d for use in asystem-in-a-package. In this embodiment, the crystal 2708 d is flippedon its back, such that the crystal bond pads are up. The top of thepackage of the crystal 2708 d is bonded or epoxied to the layer below.In an embodiment, the layer below the crystal 2708 d includes a SoC. Inanother embodiment, the layer below the crystal 2708 d includes thesubstrate. In this embodiment, the surface mount load capacitor 2706 dis too small to bridge the gap between the bond pads on the crystal 2708d. A bond wire from the bond pad of the surface mount load capacitor2706 d to the bond pad of the crystal 2708 d can bridge the gap betweenthe bond pads on the crystal 2708 d. A bond wire from the bond pad ofthe surface mount load capacitor 2706 d and a bond wire from the bondpad of the crystal 2708 d bond down to connect ground, crystaloscillator connections, the like, or any suitable combination thereof.

In other embodiments, the crystal 2708 b, the crystal 2708 c and thesurface mount load capacitor 2706 c, or the crystal 2708 d and the loadcapacitor 2706 d are flipped such that the bond pads of the crystal 2708b, the crystal 2708 c and the surface mount load capacitor 2706 c, orthe crystal 2708 d and the load capacitor 2706 d are down and setdirectly on a SoC or a substrate.

FIG. 95 illustrates another embodiment of a system-in-a-package 2800 foruse in a wireless device. SiP 2800 includes a SoC 2802, an FEIC 2804, apackaging substrate 2812, a crystal 2808, and one or more loadcapacitors 2806. The crystal 2808 is over the substrate 2812, the SoC2802 is over the crystal 2808, and the FEIC 2804 is over the SoC 2802.The SiP 2800 further includes a ground plane 2822 between the FEIC 2804and the SoC 2802. As illustrated, the footprint of the SoC 2802 islarger than the footprint of the crystal 2808, which creates an overhangvolume that is bounded by the sides of the crystal 2808, the portion ofthe SoC 2802 that extends beyond crystal 2808, and the portion of thesubstrate 2812 that is within the footprint of the SoC 2802 and notcovered by the crystal 2808. As shown in FIG. 95, the load capacitors2806 can be positioned between the substrate 2812 and the SoC 2802 inthe footprint of the SoC 2802. This can save space. In an embodiment,the load capacitors 2806 are placed in the overhang volume.

FIG. 96 illustrates another embodiment of a system-in-a-package 2900 foruse in a wireless device. SiP 2900 includes a SoC 2902, an FEIC 2904, apackaging substrate 2912, a crystal 2908, one or more load capacitors2906, and one or more supports 2924. The crystal 2908 is over thesubstrate 2912 and the SoC 2902 is over the crystal 2908. In anembodiment, the SoC 2902 is immediately adjacent to the crystal 2908;and the crystal 2908 is immediately adjacent to the substrate 2912. Inan embodiment, the footprint of the SoC 2902 is larger than thefootprint of the crystal 2908, which creates an overhang volume that isbounded by the sides of the crystal 2908, the portion of the SoC 2902that extends beyond crystal 2908, and the portion of the substrate 2912that is within the footprint of the SoC 2902 and not covered by thecrystal 2908.

Supports 2924 are placed between the SoC 2902 and the substrate 2912,near the crystal 2908, to provide support for the SoC 2902. In anembodiment, the supports 2924 are placed in the overhang volume. In anembodiment, the support 2924 includes conductive material, such ascopper or the like, and electrically connects a ground pad on the SoC2902 with a ground trace or ground plane of the substrate 2912, inaddition to providing mechanical support. In another embodiment, thesupport 2924 electrically connects a signal other than ground to a pador trace on the substrate 2912.

In an embodiment, the load capacitors 2906 are placed in the footprintof the SoC 2902 and near the crystal 2908. In an embodiment, the loadcapacitors 2906 are placed in the overhang volume. In an embodiment, theheight of the load capacitors 2906 is less than the space between theSoC 2902 and the substrate 2912. To increase the height of thecapacitors 2906, a shim or spacer 2926 can be placed on top of the loadcapacitors 2906 to fill the space between the load capacitors 2906 andthe SoC 2902. The spacer 2926 plus the load capacitors 2906 providessupport for the SoC 2902. Further, the spacer 2926 can be used tocompensate for any tilt that may occur do to stacking uneven componentsas such tilt can cause manufacturing problems when assembling any of theSiPs discussed herein, such as the SiP 2400, 2500, 2600, 2700, 2800,and/or 2900. In an embodiment, the spacer 2926 can be placed over orunder any other component that is tucked in the space between the SoC2902 and the substrate 2912. Alternatively or additionally, a spacer canbe positioned between a component (e.g., a load capacitor 2906) and thesubstrate 2912.

FIG. 97 illustrates another embodiment of a system-in-a-package 3000 foruse in a wireless device. SiP 3000 includes a SoC 3002, an FEIC 3004, apackaging substrate 3012, a crystal 3008, one or more load capacitors3006, and one or more supports 3024. The crystal 3008 is over thesubstrate 3012 and the SoC 3002 is over the crystal 3024. In anembodiment, the footprint of the SoC 3002 is larger than the footprintof the crystal 3008, which creates an overhang volume that is bounded bythe sides of the crystal 3008, the portion of the SoC 3002 that extendsbeyond crystal 3008, and the portion of the substrate 3012 that iswithin the footprint of the SoC 3002 and not covered by the crystal3008.

The supports 3024 are placed between the SoC 3002 and the substrate3012, near the crystal 3008, to provide support for the SoC 3002. In anembodiment, the supports 3024 are placed in the overhang volume. In anembodiment, the load capacitors 3006 are placed in the footprint of theSoC 3002 and near the crystal 3008. In an embodiment, the loadcapacitors 3006 are placed in the overhang volume. Further, the FEIC3004 is under the substrate 3012 on an opposite side of the substrate3012 from the crystal 3008.

In certain embodiments, any of the packaging substrates discussedherein, such as one or more of the packaging substrates 2412, 2512,2612, 2712, 2812, 2912, or 3012, include a substrate, a laminate, amulti-layer laminate, an interposer, and the like, and is configured toprovide a physical connection and traces for signal routing for at leastone component of a corresponding SiP, such as one or more of the SiP2400, 2500, 2600, 2700, 2800, 2900, or 3000.

Any of the SoCs discussed herein, such as one or more of the SoC 2402,2502, 2602, 2702, 2802, 2902, or 3002, can include a baseband subsystemand radio for a portable wireless device. In an embodiment, the radioincludes a receiver and a transmitter. In an embodiment, the basebandsubsystem includes a microprocessor configured to receive a clocksignal. In certain embodiments, any of the SoCs discussed herein, suchas one or more of the SoCs 2402, 2502, 2602, 2702, 2802, 2902, or 3002,includes an integrated circuit that integrates components of anelectronic system into a single chip. In an embodiment, the one or moreof the SoCs 2402, 2502, 2602, 2702, 2802, 2902, or 3002 includes one ormore of digital, analog, mixed-signal, and RF functions. The EM358x bySilicon Labs, Austin, Tex., is an example of a SoC that integrates aprocessor, a transceiver, memory, and serial communication on an IC.

In an embodiment, one or more of the FEICs 2404, 2504, 2604, 2704, 2804,2904, or 3004 includes a front-end system, such as SKY65249-11 bySkyworks Solutions, Woburn, Mass., for example, which includes a poweramplifier, an input filter, a power detector, harmonic filters, and aswitch in a laminate package. In certain embodiments, one or more of theFEICs 2404, 2504, 2604, 2704, 2804, 2904, or 3004 includes otherfront-end modules.

FIG. 98A1 illustrates an example crystal assembly 3108 including anenclosure, housing or case 3132 and one or more pillars 3134 along oneor more sides of the housing 3132. In an embodiment, the pillars or vias3134 include a conductive material, such as solder, metal, copper, gold,nickel gold-plated metal, the like, or any suitable alloy thereof, andthe housing 3132 includes a non-conductive material. In an embodiment,the housing 3132 further includes a lid 3130. In an embodiment, the lid3130 includes a non-conductive material, such as ceramic, glass andepoxy, woven glass and polyester, alumina, polyimide, the like, or anysuitable combination thereof.

The pillars or vias 3134 are formed from a top surface of the housing3132 to a bottom surface of the housing 3132 and provide electricaland/or thermal conduction. In an embodiment, the pillars 3134 are formedat least partially within the sides of the housing 3132. In anotherembodiment, the housing 3132 is formed with one or more tubes along oneor more sides of the housing 3132, such that filling the tubes withsolder forms the pillars 3134. In another embodiment, the pillars 3134are formed as cylindrical, rectangular, or the like, tubes or columnsoutside, partially with, or within the housing 3132.

In an embodiment, the tops and the bottoms of the pillars 3134 form pads3136 around the perimeter of the housing 3132. In another embodiment,the pillars 3134 are in electrical communication with the pads 3136formed along the top and bottom surfaces of the pillars 3134. In anembodiment, the pads 3136 are configured as surface mount pads. Inanother embodiment, the pads 3136 are wire bondable. In anotherembodiment, the pads 3136 are configured to be soldered to solder ballsof ball-grid array packaged integrated circuit.

In an embodiment, the lid 3130 includes a ceramic substrate materialand/or other non-conductive material and can be configured as a routingsubstrate, interposer, or circuit board. As illustrated in FIG. 98A1,the lid 3130 further includes routing 3133 and pads 3135, where therouting 3133 is configured to carry a signal between the pads 3135. Inan embodiment, the routing and pads are formed on the lid 3130 accordingto routing substrate, interposer, or circuit board fabricationtechniques. In an embodiment, a first wire bond 3131 is bonded to afirst pillar 3134 and a second wire bond 3131 is bonded to a secondpillar 3134. Wire bonds 3131 communicate a signal from one of the wirebond-connected pillars 3134 through the pads 3135 and trace 3133 on thelid 3130 to the other of the wire bond-connected pillar 3134.

FIG. 98A2 illustrates the crystal assembly 3108 further including aconductive layer 3137 wrapped around four sides of the crystal assembly3108. The conductive layer 3137 is in electrical communication with eachof the pillars 3134. In an embodiment, the wrapped conductive layer 3137includes copper, plated copper, where the plating material can besolder, tin, gold over nickel, and the like, or any other conductivematerial. In another embodiment, the wrapped conductive layer can beplated onto the one, two, three, or four sides of the crystal assembly3108, where the plating material can be solder, tin, gold over nickel,and the like.

In other embodiments, the wrapped conductive layer 3137 wraps aroundone, two, three, or four of the sides of the crystal assembly 3108 andis in electrical communication with the pillars 3134 of the one, two,three, or four of the sides, respectively. In an embodiment, the pillars3134 in electrical communication with the wrapped conductive layer 3137are connected to ground. The combination of the grounded pillars 3134and the wrapped conductive layer 3137 forms a “super ground”. The superground can reduce inductance coupling onto the ground and provide bettersignal isolation.

In another embodiment, the pillars 3134 in electrical communication withthe wrapped conductive layer 3137 form a radio frequency (RF) shield toshield the devices within the cavity of the enclosure 3132 from RFinterference.

In another embodiment, the pillars 3134 in electrical communication withthe wrapped conductive layer 3137 form a heat sink to dissipate heat.For example, the pillars 3134 and wrapped conductive layer 3137 candissipate heat generated by a power amplifier placed above or below thecrystal assembly 3108 and in thermal contact with the heat sink formedby the pillars 3134 and the wrapped conductive layer 3137.

FIG. 98B1 illustrates a cross-sectional view of the example crystalassembly 3108 including the lid 3130, the housing 3132, and one or morepillars 3134. The crystal assembly 3108 further includes a crystal 3138housed within the housing 3132. As illustrated, the crystal assembly3108 further includes one or more load capacitors 3140, oscillatorcircuitry 3142, and an FEIC 3144 housed within the housing 3132 of thecrystal assembly 3108. One or more integrated circuit die can be housedwithin the housing 3132.

FIG. 98B2 illustrates a cross-sectional view of the example crystalassembly 3108 including the lid 3130, the housing 3132, and one or morepillars 3134. The crystal assembly 3108 further includes the crystal3138 housed within the housing 3132. As illustrated in FIG. 98B2, thecrystal assembly 3108 further includes the one or more load capacitors3140, the oscillator circuitry 3142, and a surface acoustic wave (SAW)device 3145 housed within the housing 3132 of the crystal assembly 3108.Examples of SAW devices 3145 include filters, delay lines, correlatorsand DC to DC converters. One or more integrated circuit die are housedwithin the housing 3132.

The embodiment of FIG. 98B2 illustrates the SAW device 3145, such as aSAW filter, and the crystal 3138 in the same physical cavity formedwithin the crystal assembly 3108. In an embodiment, the crystal assembly3108 is hermetically sealed. In another embodiment, the cavity isgas-filled, and the crystal assembly is hermetically sealed. Placing theSAW device and the crystal in the same physical cavity canadvantageously save space on the module.

FIG. 98C illustrates a bottom view of the example crystal assembly 3108.In an embodiment, the crystal assembly 3108 further includes one or morepads 3152 in communication with one or more of the components 3138,3140, 3142, 3144 housed within the housing 3132.

FIG. 98D illustrates an example system-in-a-package 3100 including aflip chip SoC 3102 above the crystal assembly 3108. As illustrated, thelid 3130 of the crystal assembly 3108 is disposed between the crystal3138 and the flip chip SoC 3102. In an embodiment, a ball-grid array3106 of the flip-chip SoC 3102 is in communication with one or more ofthe pillars 3134 and/or pads 3136. The system-in-a-package 3100 furtherincludes a substrate 3104 in electrical communication with the flip-chipSoC 3102.

FIG. 98E illustrates an example system-in-a-package 3110 including theflip chip SoC 3102 beneath the crystal assembly 3108. As illustrated inFIG. 98E, the packaging of the crystal assembly 3108 is disposed betweenthe crystal 3138 and the flip chip SoC 3102. In an embodiment, theball-grid array 3106 of the flip-chip SoC 3102 is in communication withone or more of the pillars 3134 and/or pads 3136. Thesystem-in-a-package 3110 further includes the substrate 3104 inelectrical communication with the flip-chip SoC 3102.

FIG. 98F illustrates an example circuit assembly 3120 including anintegrated circuit 3146 mounted to the lid 3130 of the crystal assembly3108. Wirebonds 3148 electrically connect pads 3150 of the integratedcircuit 3146 to the pillars 3134 or pads 3136. In an embodiment, theintegrated circuit 3146 includes a front-end-integrated-circuit (FEIC).In another embodiment, the integrated circuit 3146 includes at least aportion of one or more of radio frequency transmitter circuitry andradio frequency receiver circuitry.

Any suitable crystal or crystal assembly discussed herein can bepackaged without a load capacitor. Any suitable crystal or crystalassembly discussed herein can be packaged with one or more loadcapacitors. Any suitable crystal or crystal assembly discussed hereincan form at least part of a crystal oscillator.

Any of the crystals discussed herein can include a CX2016DB16000D0HZLC1by Kyocera of Yamagata, Japan. Crystals discussed herein can have asuitable dimension for a particular application. For example, in someinstances, any of the crystals discussed herein can be is approximately1.60 mm±0.10 mm by approximately 2.00 mm±0.10 mm.

Table 1 illustrates example ratings and Table 2 illustrates exampleelectrical characteristics for an embodiment of the crystal 2408, 2508,2608, 2708, 2808, 2908, 3008, 3138.

TABLE 1 Items SYMB. Rating Unit Operating Temperature Topr −25 to +75 °C. Range Storage Temperature Range Tstg −40 to +85 ° C.

TABLE 2 Electrical Specification Items SYMB. Min Typ. Max Unit TestCondition Mode of Fundamental Vibration Nominal F0 16 MHz FrequencyNominal T_(NOM) +25 ° C. Temperature Load CL 8.0 pF CapacitanceFrequency df/F −20.0 +20.0 PPM +25 ± 3° C. Tolerance Frequency df/F−20.0 +20.0 −25 to +75° C. Temperature Characteristics Frequency −1.0+1.0 1^(st) Year Aging Rate +25 ± 3° C. Equivalent ESR 150 Ω SeriesResistance Drive Level Pd 0.01 100 μW Insulation IR 500 MΩ 100 V (DC)Resistance

As indicated in Table 2, the equivalent series resistance (ESR) of thecrystal 2408, 2508, 2608, 2708, 2808, 2908, 3008, 3138 is approximately150 Ohms. In another embodiment, the ESR is approximately 100 Ohms. In afurther embodiment, ESR is between approximately 100 Ohms andapproximately 200 Ohms. In another embodiment, the ESR is betweenapproximately 75 Ohms and approximately 200 Ohms, between approximately75 ohms and approximately 150 Ohms, between approximately 75 Ohms andapproximately 100 Ohms, less than approximately 200 Ohms, less thanapproximately 150 Ohms, less than approximately 100 Ohms, or less thanapproximately 75 Ohms.

In other embodiments, the any of the crystals 2408, 2508, 2608, 2708,2808, 2908, 3008, 3138 can have different specifications.

FIGS. 99-105 illustrate example novel stacking options for passivecomponents, surface mount devices (SMD), integrated circuits, stackedassemblies, laminates, and combinations thereof.

FIG. 99 illustrates an example stacked assembly 3200 that includes abottom layer 3202, a top layer 3204 positioned over the bottom layer3202, and one or more supports 3206 in between the top layer 3204 andthe bottom layer 3202 to provide support for the top layer 3204. In anembodiment, one end of the support 3206 is immediately adjacent to thebottom layer 3202 and an opposite end of the support 3206 is immediatelyadjacent to the top layer 3204.

The supports 3206 can be positioned such that an overhang 3208 is formedon at least both sides of the stacked assembly 3200 between an outside3206 a of the support 3206, the bottom layer 3202, and the top layer3204. Further, the supports 3206 can be positioned such that a cavity3210 is formed between insides 3206 b of the supports 3206, the bottomlayer 3202, and the top layer 3204.

The bottom layer 3202 can be, for example, a laminate, an IC, a die, asurface mount device, a crystal, a SoC, or the like. In an embodiment,an IC, a die, a flip-chip die, a wirebond die, a surface mount device, acrystal, SoC, and an assembly, for example, can be placed within theoverhang 3208 and immediately adjacent to the bottom layer 3202. Inanother embodiment, an IC, a die, a flip-chip die, a wirebond die, asurface mount device, a crystal, SoC, and an assembly, for example, canbe placed within the cavity 3210 and immediately adjacent to the bottomlayer 3202. In a further embodiment, the assembly within the cavity 3210or the overhang 3208 can be any suitable assembly described herein.

The top layer 3204 can be, for example, a laminate, an IC, a die, asurface mount device, a crystal, a SoC, or the like. In a furtherembodiment, the laminate includes a dual sided laminate and either orboth sides of the dual-sided laminate can comprise an IC, a die, asurface mount device, a crystal, a SoC, or the like. In an embodiment,the top layer 3204 includes a ball grid array with one or more surfacemount devices in communication with a respective one or more solderballs of the ball grid array.

In an embodiment, the support 3206 includes an IC, a die, a crystal, asurface mount device, a rectangular or cylindrical pillar or post, andthe like, to support the top layer 3204. In an embodiment, the support3206 functions as a mechanical support. In another embodiment, thesupport 3206 functions as a mechanical support as well as providing anelectrical function. For example, a surface mount device, such as aresistor, a capacitor, or an inductor, could form a connection betweenthe bottom layer 3202 and the top layer 3204 and be part of anelectrical circuit. In another embodiment, the support 3206 includes aconductive material and forms a ground connection between the bottomlayer 3202 and the top layer 3204.

FIGS. 100A1-100D illustrates example bonding configurations from a bondsource 3370 to surface mount devices 3312, 3332, 3342, 3352. In anembodiment, the bond source 3370 includes a die, an IC, a surface mountdevice, a laminate or any other item that a first end of a wire bond canbe bonded to. In an embodiment, bond source 3370 is immediately adjacentto a laminate 3304. In an embodiment, laminate 3304 is configured tofurther route signals traveling along one or more of the surface mountconnections of FIGS. 100A-100D.

FIG. 100A illustrates a first wire bond 3310 bonded between the bondsource 3370 and a first end of the horizontally oriented surface mountdevice 3312, and a second wire bond 3320 bonded between the bond source3370 and a second end of the surface mount device 3312 to form a seriesconnection between the bond source 3370 and the surface mount device3312.

FIG. 100B illustrates a wire bond 3330 bonded between the bond source3370 and a first end of the horizontally oriented surface mount device3332, where a second end of the surface mount device 3332 is inelectrical communication with one or more traces and/or pads formed onthe laminate 3304.

FIG. 100C illustrates a wire bond 3340 bonded between a first end of thevertically oriented surface mount device 3342 where a second end of thesurface mount device 3342 is in electrical communication with one ormore traces and/or pads formed on the laminate 3304.

FIG. 100D illustrates a wire bond 3350 bonded between a first end of thevertically oriented surface mount device 3352 and another wire bond 3360bonded between the first end of the surface mount device 3352 andbondable device 3362 to form a shunt or parallel connection between thesurface mount device 3352 and the bondable device 3362. The surfacemount device 3352 is mounted on the laminate 3304 in a vertical positionas illustrated. In another embodiment, the surface mount device 3352 ismounted on the laminate 3304 in a horizontal position. The bondabledevice 3362 can be a surface mount device, a die, an IC, part of thelaminate 3304, or any device with a bondable surface.

FIGS. 101A1-101D2 illustrate example space saving stackingconfigurations and corresponding example circuit diagrams for surfacemount parts, components, devices, the like, or any suitable combinationthereof. Stacking the surface mount components to form circuits orportions of circuits saves physical layout space on substrates, such aslaminate substrates, compared to mounting each surface mount componentdirectly onto the substrate. Further, traces can interconnect thesurface mount components on the substrate to form portions of anelectrical circuit. The direct connection between two stacked surfacemount parts can eliminates at least one trace from the substrate to saveadditional space. In an embodiment, the stacked surface mount componentsare included in one or more filter circuits configured to filter radiofrequency signals. The surface mount devices include one or moreinductors, one or more capacitors, one or more resistors, or anysuitable combination thereof. The surface mount components can includeactive and/or passive surface mount devices in various applications.

FIG. 101A1 illustrates a surface mount stacking assembly 3410 includinga first horizontally positioned surface mount device 3412 stacked overand immediately adjacent to a second horizontally positioned surfacemount device 3414, where the second surface mount device 3414 is overand immediately adjacent to a bottom layer 3416. In an embodiment, thecontacts of the first surface mount device 3412 are in electricalcommunication with respective contacts of the second surface mountdevice 3414.

FIG. 101A2 illustrates an example filter circuit 3415. In an embodiment,the stacking configuration 3410 includes the filter circuit 3415. Asillustrated, the filter circuit 3415 is a parallel LC circuit. In otherembodiments, other filter circuits and/or other circuits can be formedusing the surface mount stacking assembly 3410.

FIG. 101B1 illustrates a surface mount stacking assembly 3420 includinga first vertically oriented surface mount device 3422 stacked on endover and immediately adjacent to a second vertically oriented surfacemount device 3424. A first end of the surface mount device 3422 is inelectrical communication with a first end of the second surface mountdevice 3424, and a second end of the second surface mount device 3424 isover and immediately adjacent to a bottom layer 3426. In an embodiment,the second end of the second surface mount device 3424 is in electricalcommunication with one or more pads and/or traces on the bottom layer3426.

FIG. 101B2 illustrates an example filter circuit 3425. In an embodiment,the stacking configuration 3420 includes the filter circuit 3425. Asillustrated, the filter circuit 3425 includes two resistors in serieswith each other. In other embodiments, other filter circuits and/orother circuits can be formed using the surface mount stacking assembly3420.

FIG. 101C1 illustrates a surface mount stacking assembly 3430 includinga horizontally oriented first surface mount device 3432, a horizontallyoriented second surface mount device 3434, and a horizontally orientedthird surface mount device 3438. In an embodiment, the first surfacemount device 3432 and the second surface mount device 3434 are over andimmediately adjacent to a bottom layer 3436 and spaced apart such that afirst end of the third surface mount device 3438 is stacked over a firstend of the first surface mount device 3432 and a second end of the thirdsurface mount device 3434 is stacked over a first end of the secondsurface mounted device 3434. In an embodiment, the surface mount devices3432, 3434, 3438 are electrically connected in series. In an embodiment,the stacking configuration 3430 has a smaller footprint than thefootprint formed by mounting three surface mount devices on the bottomlayer 3436 to form a series connection.

FIG. 101C2 illustrates a surface mount stacking assembly 3440 includinga first vertically oriented surface mount device 3442, a secondvertically oriented surface mount device 3444, and a third horizontallyoriented surface mount device 3448. The first surface mount device 3442is over and immediately adjacent to a bottom layer 3446 such that afirst end of the first surface mount device 3442 is in electricalcommunication with pads or traces on the bottom layer 3446. The secondsurface mount device 3444 is over and immediately adjacent to the bottomlayer 3446. A first end of the second surface mount device 3442 can bein electrical communication with one or more pads and/or traces on thebottom layer 3446.

Further, the first and second surface mount devices 3442 and 3444,respectively, of FIG. 101C2 are spaced apart such that a first end ofthe third surface mount device 3448 is over and in electricalcommunication with a second end of the first surface mount device 3442and a second end of the third surface mount device 3448 is over and inelectrical communication with a second end of the second surface mountdevice 3444.

In an embodiment, the surface mount stacking assemblies 3430 and/or 3440include a pi (7) filter topology. An example pi filter circuit 3445 isillustrated in FIG. 101C3. As illustrated, the pi filter circuit 3445includes two capacitors and an inductor. In an embodiment, the stackingconfiguration 3440 has a smaller footprint than the footprint formed bymounting three similar surface mount devices on the bottom layer 3436and/or 3446 to form the pi filter circuit.

In another embodiment, the stacking configuration 3440 can be flippedover such that surface mount device 3448 is over the bottom layer 3446,and surface mount devices 3442 and 3444 are over surface mount device3448.

FIG. 101D1 illustrates a surface mount stacking assembly 3450 includinga first surface mount device 3452, a second surface mount device 3454, athird surface mount device 3458, and a fourth surface mount device 3460.In a first embodiment, as illustrated in FIG. 101D1, the first, second,and third surface mount devices 3452, 3454, 3458 form the surface mountstacking assembly 3440 over and immediately adjacent to a bottom layer3456, and the fourth surface mount device 3460 is stacked over andimmediately adjacent to the third surface mount device 3458. In anembodiment, pads of the fourth surface mount device 3460 are inelectrical communication with corresponding pads of the third surfacemount device 3458.

In a second embodiment (not illustrated), the first, second, and thirdsurface mount devices 3452, 3454, 3458 form the surface mount stackingassembly 3440 over and immediately adjacent to the bottom layer 3456,and the fourth surface mount device 3460 is stacked beside andimmediately adjacent to the third surface mount device 3458 and alsoover and immediately adjacent to the first and second surface mountdevices 3452, 3454. In an embodiment, pads of the fourth surface mountdevice 3460 are in electrical communication with corresponding pads ofthe third surface mount device 3458 and the corresponding pads of thefirst and second surface mount devices 3452, 3454.

In a third embodiment (not illustrated), the first, second, and thirdsurface mount devices 3452, 3454, 3458 form the stacking configuration3430 over and immediately adjacent to the bottom layer 3456, and thefourth surface mount device 3460 is stacked over and immediatelyadjacent to the third surface mount device 3458. In an embodiment, padsof the fourth surface mount device 3460 are in electrical communicationwith corresponding pads of the third surface mount device 3458.

In a fourth embodiment (not illustrated), the first, second, and thirdsurface mount devices 3452, 3454, 3458 form the surface mount stackingassembly 3430 over and immediately adjacent to the bottom layer 3456,and the fourth surface mount device 3460 is stacked beside andimmediately adjacent to the third surface mount device 3458 and alsoover and immediately adjacent to the first and second surface mountdevices 3452, 3454. In an embodiment, pads of the fourth surface mountdevice 3460 are in electrical communication with corresponding pads ofthe third surface mount device 3458 and the corresponding pads of thefirst and second surface mount devices 3452, 3454.

In a fifth embodiment (not illustrated), the surface mount stackingassembly 3450 can be flipped over such that surface mount device 3460 isover the bottom layer 3456, surface mount device 3458 is over surfacemount device 3460, and surface mount devices 3452 and 3454 are each overa different end of surface mount device 3458.

In an embodiment, the surface mount stacking assembly 3450 includes aband-reject or notch filter topology that can be configured to form anotch or reject at specific frequencies. An example band-reject filtercircuit 3455 is illustrated in FIG. 101D2. In an embodiment, a surfacemount stacking assembly that includes a first surface mount stackingassembly 3450 beside a second surface mount stacking assembly 3450 suchthat both the first and second surface mount stacking assemblies 3450share surface mount device 3454 and implement a band-reject filtercircuit with a notch at two specified frequencies.

In an embodiment, the stacking configuration 3450 has a smallerfootprint than the footprint formed by mounting four surface mountdevices on the bottom layer 3456 to form the band-reject or notch filtertopology. Since any node or pad of any of the surface mount devices3412, 3414, 3422, 3424, 3432, 3434, 3438, 3442, 3444, 3448, 3452, 3454,3458, 3460 can be configured for bonding, additional surface mountdevices and/or various combinations of the stacking structures 3410,3420, 3430, 3440, 3450, for example, can be combined to createstructures with a more complex topology.

Surface mount devices 3412, 3414, 3422, 3424, 3432, 3434, 3438, 3442,3444, 3448, 3452, 3454, 3458, 3460 can be, for example, passivecomponents, such as capacitors, resistors, or inductors, discretesemiconductors, such as transistors or diodes, integrated circuits, thelike, or any suitable combination thereof, and can have relatively shortpins or leads of various styles, flat contacts, a matrix of solder balls(BGAs), or terminations on the body of the component.

FIG. 101E illustrates an example circuit board layout 3470 of amultichip module. In an embodiment, the layout 3470 forms at least aportion of a circuit, SiP, SoC, or MCM for use in a portabletransceiver. In an embodiment, components L3, C2, C3 form a firstantenna filter, components L4, C6, C7 form a second antenna filter, andcomponents L5, C8, C9 form a third antenna filter. As illustrated in thelayout 3470, the footprint of the first antenna filter includes thefootprint of each of the components L3, C2, C3 and the traces betweenthe components. Likewise the footprint of the second antenna filterincludes the footprint of each of the components L4, C6, C7 and thecorresponding traces, and the footprint of the third antenna filterincludes the footprint of each of the components L5, C8, C9 and thecorresponding traces. Further, the layout 3470 includes traces thatprovide electrical connections between device U1 and several components,such as at least C15, C26, C29, C32, C33. These traces also occupy spaceon the circuit board layout 3470.

FIG. 101F illustrates an example circuit board layout 3480 with examplebonding configurations and example stacking configurations that reducethe form factor of the circuitry. In FIG. 101F, components L2, C2, C3are stacked to form a first surface mount stacking assembly 3490,components L4, C6, C7 have been stacked to form a second surface mountstacking assembly 3490, and components L5, C8, C9 have been stacked toform a third surface mount stacking assembly 3490. Components C2, C3,C6, C7, C8, and C9 are capacitors. Components L2, L4, and L5 areinductors. In an embodiment, the surface mount stacking assembly 3490 isconfigured as the surface mount stacking assembly 3440 and thecomponents are electrically connected as illustrated in circuit 3445. Insome embodiments, the surface mount stacking assemblies 3490 includehigh-pass filters, low-pass filters, band pass filters, at least aportion of an output matching network, the like, or any suitablecombination thereof.

Advantageously, surface mount stacking assemblies 3490 have a smallerfootprint (take up less physical area on the circuit board layout) thanthe individual surface mount components L3, L4, L5, C2, C3, C6, C7, C8,C9 of the circuit board layout 3407 of FIG. 101E. For example, thelayout 3480 can be smaller than the layout 3470 of FIG. 101E. This canbe significant as electronic devices continue to shrink in size.Alternatively or additionally, smaller and more expensive componentsthat are used in layout 3470 due to space constraints can be replacedwith larger, less expensive components in the layout 3480.

In FIG. 101F, traces between components C15, C26, C29, C32, C33 anddevice U1 have been removed and replaced with wire bonds 3485 thatelectrically couple components C15, C26, C29, C32, C33 with anassociated wire bondable location on device U1 In an embodiment, firstends of the wire bonds 3485 are bonded directly to the correspondingsurface mount component and second ends of the wire bonds 3485 arebonded directly to a corresponding location on the device U1. In anotherembodiment, first ends of the wire bonds 3485 are bonded directly to thecorresponding surface mount component and second ends of the wire bonds3485 are bonded directly a bondable location on the circuit board layout3480. Examples of wire bonds 3485 are illustrated in FIGS. 100A-100D.Advantageously, replacing the traces on the layout 3480 with the wirebonds 3485 allows the layout 3480 to be smaller than the layout 3470.Alternatively or additionally, smaller and more expensive componentsthat are used in layout 3470 due to space constraints can be replacedwith larger, less expensive components in the layout 3480.

FIG. 102 illustrates an example stacked assembly 3500 including a firstintegrated circuit die 3502 mounted over and immediately adjacent to alaminate 3506. The stacked assembly 3500 further includes a secondintegrated circuit die 3504 stacked over and immediately adjacent to thefirst integrated circuit die 3502. The first and second integratedcircuit die 3502, 3504 are in electrical communication with pads andtraces on the laminate 3506 by way of wire bonds 3508.

FIG. 103 illustrates an example stacked assembly 3600 including a firstintegrated circuit die 3602 in electrical communication with a laminate3606 by way of one or more wire bonds 3608. The stacked assembly 3600further includes a second integrated circuit die 3604 over andimmediately adjacent to the first integrated circuit die 3602. The firstintegrated circuit die 3602 is configured to electrically connect withthe second integrated circuit die 3604. In an embodiment, the secondintegrated circuit die 3604 includes a crystal. In another embodiment,the second integrated circuit die 3604 is configured as a surface mountdevice. In a further embodiment, the second integrated circuit die 3604is configured as a flip chip die. Such a flip chip die can beelectrically connected to other components of the stacked assembly 3600,such as the second integrated circuit die 3604, by way of bumps.

In an embodiment, any of the stacking configurations 3410, 3420, 3430,3440, 3450 and/or any of the stacked assemblies 3500, 3600 can bepositioned in the cavity 3210 or the overhang 3206 of FIG. 99.

FIG. 104 illustrates an example stacked assembly 3700 including supports3724 a, 3724 b and a spacer 3726 that provide support for a top layer3708 over a bottom layer 3706. A potential problem with the supports3724 a, 3724 b are error tolerances. For example, one support 3724 acould be higher than another support 3724 b. A spacers 3726, forexample, can be placed in between the support 3724 b and the top layer3708 or the bottom layer 3706 to offset any difference in height betweensupports. In an embodiment, the spacers 3726 include a material that canbe “squished” or compressed to fit in the gap that results from anydifference in height between support 3724 a and support 3724 b.

FIG. 105 illustrates an example circuit assembly 3800 including aplurality of stacked assemblies 3810, 3820, 3830, a plurality of wirebonds 3818, and a bottom layer 3806. Stacked assembly 3800 illustratesone embodiment of multiple stacked assemblies 3810, 3820, 3830 that canbe assembled over and immediately adjacent to the bottom layer 3806. Inan embodiment, stacked assembly 3820 fits at least partially in anoverhang provided by stacked assembly 3810. The illustrated circuitassembly 3800 further includes wire bonds 3818 providing electricalcommunication between the stacked assembly 3810 and pads and/or traceson the bottom layer 3806, between stacked assembly 3810 and stackedassembly 3820, and between stacked assembly 3810 and stacked assembly3830.

The circuit assemblies described herein can further include an overmoldstructure formed of a molding material. The molding material is pliableand moldable in process and becomes hard when cured. In an embodiment,the overmold structure covers at least a portion of the top of thesubstrate and one or more components located on the top portion of thesubstrate, where the bottom surface of the substrate is free from theovermold structure in order to make electrical connections to thecircuit assembly. In other embodiments, the overmold structure covers atleast a portion of the bottom surface of the substrate and one or morecomponents located on the bottom of the substrate. Electricalconnections to the circuit assemblies described herein can be made fromthe top of the substrate.

FIG. 106 is an example block diagram of a system in a package (SiP) 3900including a crystal 3908, a SoC 3902, and an FEIC 3904. The SiP 3900further includes connectivity 3906 to provide signal interconnections,packaging 3912, such as a package substrate and/or an overmold, forpackaging of the circuitry, and other circuitry 3910, such as loadcapacitors associated with the crystal 3908, filters, modulators,demodulators, down converters, the like, or any suitable combinationthereof. The SiP 3900 can include any suitable features of one or moreof the SiPs 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3500,3600, 3700, or 3800.

FIG. 107 is an example block diagram illustrating a wireless device 4000including a SiP 4100, where the SiP 4100 includes a SoC 4102, an FEIC4104, and a crystal 4108. In an embodiment, the wireless device 4000includes a portable transceiver 4000. In an embodiment, SoC 4102includes a baseband subsystem 4010, receiver 4070, and transmitter 4050.The crystal 4108 supplies clock information for the SoC 4102. In anembodiment, SiP 4100 includes any suitable features of one or more ofthe SiPs 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3500,3600, 3700, 3800, or 3900.

The illustrated wireless device 4000 includes a speaker 4002, a display4004, a keyboard 4006, and a microphone 4008, all connected to thebaseband subsystem 4010. A power source 4042, which may be a directcurrent (DC) battery or other power source, is also connected to thebaseband subsystem 4010 to provide power to the wireless device 4000. Ina particular embodiment, wireless device 4000 can be, for example butnot limited to, a portable telecommunication device such as a mobilecellular telephone. The speaker 4002 and the display 4004 receivesignals from baseband subsystem 4010. Similarly, the keyboard 4006 andthe microphone 4008 supply signals to the baseband subsystem 4010. Thekeyboard 4006 can be implemented by a touch screen displayed by thedisplay 4004 in certain implementations.

The baseband subsystem 4010 includes a microprocessor (pP) 4020, memory4022, analog circuitry 4024, and a digital signal processor (DSP) 4026in communication by way of bus 4028. Bus 4028, although shown as asingle bus, may be implemented using multiple busses connected asdesired among the subsystems within the baseband subsystem 4010. Thebaseband subsystem 4010 may also include one or more of an applicationspecific integrated circuit (ASIC) 4032 or a field programmable gatearray (FPGA) 4030.

The microprocessor 4020 and memory 4022 provide the signal timing,processing, and storage functions for wireless device 4000. The analogcircuitry 4024 provides the analog processing functions for the signalswithin baseband subsystem 4010. In FIG. 107, the baseband subsystem 4010provides control signals to a transmitter 4050, a receiver 4070, and apower amplifier circuit 4080.

A wireless device can include more or fewer components than illustratedin FIG. 107. The control signals provided by the baseband subsystem 4010control the various components within the wireless device 4000. Thefunction of the transmitter 4050 and the receiver 4070 may be integratedinto a transceiver.

The illustrated baseband subsystem 4010 also includes ananalog-to-digital converter (ADC) 4034 and digital-to-analog converters(DACs) 4036 and 4038. In this example, the DAC 4036 generates in-phase(I) and quadrature-phase (Q) signals provided to signal lines 4040connected to a modulator 4052. The ADC 4034, the DAC 4036, and the DAC4038 also communicate with the microprocessor 4020, the memory 4022, theanalog circuitry 4024, and the DSP 4026 by way of bus 4028. The DAC 4036converts the digital communication information within baseband subsystem4010 into an analog signal for transmission to the modulator 4052 by wayof connection 4040. Connection 4040, while shown as two directed arrows,carries the information that is to be transmitted by the transmitter4050 after conversion from the digital domain to the analog domain.

The transmitter 4050 includes the modulator 4052, which modulates theanalog information on connection 4040 and provides a modulated signal toupconverter 4054. The upconverter 4054 transforms the modulated signalto an appropriate transmit frequency and provides the upconverted signalto the power amplifier circuit 4080. The power amplifier circuit 4080amplifies the signal to an appropriate power level for the system inwhich the wireless device 4000 is designed to operate.

The data on connection 4040 is generally formatted by the basebandsubsystem 4010 into in-phase (I) and quadrature (Q) components. The Iand Q components may take different forms and be formatted differentlydepending upon the communication standard being employed.

The front-end module 4104 includes the power amplifier (PA) circuit 4080and a switch/low noise amplifier (LNA) circuit 4072 including a lownoise amplifier. In an embodiment, the switch/low noise amplifiercircuit 4072 further includes an antenna system interface that mayinclude, for example, a diplexer (or a duplexer) having a filter pairthat allows simultaneous passage of both transmit signals and receivesignals.

The power amplifier circuit 4080 supplies the amplified transmit signalto the switch/low noise amplifier circuit 4072. The amplified transmitsignal is supplied from the front-end module 4004 to the antenna 4060when the switch is in the transmit mode.

A signal received by antenna 4060 will be provided from the switch/lownoise amplifier circuit 4072 of the front-end module 4004 to thereceiver 4070 when the switch is in the receive mode. The low noiseamplifier amplifies the received signal.

If implemented using a direct conversion receiver (DCR), thedownconverter 4074 converts the amplified received signal from an RFlevel to a baseband level (e.g., to a direct current (DC) level), or anear-baseband level (e.g., approximately 100 kHz). Alternatively, theamplified received RF signal may be downconverted to an intermediatefrequency (IF) signal in certain applications. The downconverted signalis provided to the filter 4076. The filter 4076 includes at least onefilter stage to filter the received downconverted signal.

The filtered signal is sent from the filter 4076 to the demodulator4078. The demodulator 4078 recovers the transmitted analog informationand supplies a signal representing this information by way of connection4086 to the ADC 4034. The ADC 4034 converts the analog information to adigital signal at baseband frequency and the signal propagates by way ofbus 4028 to the DSP 4026 for further processing.

Many other variations of stacked components than those described hereinwill be apparent from this disclosure. Different combinations of thecomponents illustrated in SiPs 2400, 2500, 2600, 2700, 2800, 2900, 3000,3100, 3200, 3500, 3600, 3700, or 3800 are possible to form a variety ofSiPs that can be used in wireless devices to provide smaller footprints,reduced parasitic capacitance, decreased signal cross-coupling, thelike, or any combination thereof.

APPLICATIONS, TERMINOLOGY, AND CONCLUSION

Any of the embodiments described herein can be implemented inassociation with wireless communications devices, such as any suitableInternet of Things (IoT) device. The principles and advantages of theembodiments can be implemented in any suitable systems, packaged module,integrated circuit, or the like that could benefit from any feature ofone or more embodiments described herein. The teachings herein areapplicable to a variety of systems. Examples of such systems include,but are not limited to, mobile phones, tablets, base stations, networkaccess points, customer-premises equipment (CPE), IoT-enabled objects,laptops, and wearable electronics. Thus, the embodiments herein can beincluded in various electronic devices, including, but not limited to,consumer electronic products. Although this disclosure includes someexample embodiments, the teachings described herein can be applied to avariety of structures. Any of the principles and advantages discussedherein can be implemented in association with radio frequency circuitsconfigured to process signals in a range from about 30 kHz to 300 GHz,such as in a range from about 450 MHz to 6 GHz.

Aspects of this disclosure can be implemented in various electronicdevices. Examples of the electronic devices can include, but are notlimited to, consumer electronic products, parts of the consumerelectronic products such as integrated circuits and/or packaged radiofrequency modules, uplink wireless communication devices, wirelesscommunication infrastructure, electronic test equipment, etc. Examplesof the electronic devices can include, but are not limited to, a mobilephone such as a smart phone, a wearable computing device such as a smartwatch or an ear piece, a telephone, a television, a computer monitor, acomputer, a modem, a hand-held computer, a laptop computer, a tabletcomputer, a personal digital assistant (PDA), a microwave, arefrigerator, an automobile, a stereo system, a DVD player, a CD player,a digital music player such as an MP3 player, a radio, a camcorder, acamera, a digital camera, a portable memory chip, a washer, a dryer, awasher/dryer, a copier, a facsimile machine, a scanner, amulti-functional peripheral device, a wrist watch, a clock, etc.Further, the electronic devices can include unfinished products.

Unless the context requires otherwise, throughout the description andthe claims, the words “comprise,” “comprising,” “include,” “including”and the like are generally to be construed in an inclusive sense, asopposed to an exclusive or exhaustive sense; that is to say, in thesense of “including, but not limited to.” The word “coupled”, asgenerally used herein, refers to two or more elements that may be eitherdirectly connected, or connected by way of one or more intermediateelements. Likewise, the word “connected”, as generally used herein,refers to two or more elements that may be either directly connected, orconnected by way of one or more intermediate elements. Additionally, thewords “herein,” “above,” “below,” and words of similar import, when usedin this application, shall refer to this application as a whole and notto any particular portions of this application when appropriate. Wherethe context permits, words in the above Detailed Description using thesingular or plural number may also include the plural or singularnumber, respectively. The word “or” in reference to a list of two ormore items, that word covers all of the following interpretations of theword: any of the items in the list, all of the items in the list, andany combination of the items in the list.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or withoutauthor input or prompting, whether these features, elements and/orstates are included or are to be performed in any particular embodiment.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel apparatus, methods, andsystems described herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe methods and systems described herein may be made without departingfrom the spirit of the disclosure. For example, while blocks arepresented in a given arrangement, alternative embodiments may performsimilar functionalities with different components and/or circuittopologies, and some blocks may be deleted, moved, added, subdivided,combined, and/or modified. Each of these blocks may be implemented in avariety of different ways. Any suitable combination of the elements andacts of the various embodiments described above can be combined toprovide further embodiments. The accompanying claims and theirequivalents are intended to cover such forms or modifications as wouldfall within the scope and spirit of the disclosure.

What is claimed is:
 1. A packaged module comprising: a low noiseamplifier within a package, the low noise amplifier including a firstinductor, an amplification circuit, and a second inductor magneticallycoupled to the first inductor to provide negative feedback to linearizethe low noise amplifier; and a multi-mode power amplifier circuit withinthe package, the multi-mode power amplifier circuit including a stackedoutput stage including a transistor stack of two or more transistors,and the multi-mode power amplifier circuit including a bias circuitconfigured to control a bias of at least one transistor of thetransistor stack based on a mode of the multi-mode power amplifiercircuit.
 2. The packaged module of claim 1 further comprising a packagesubstrate, a radio frequency shielding structure extending above thepackage substrate and enclosing the low noise amplifier and themulti-mode power amplifier circuit, and an antenna on the packagesubstrate external to the radio frequency shielding structure.
 3. Thepackaged module of claim 2 wherein the antenna is a multi-layer antenna.4. The front end system of claim 1 further comprising a die supported bya package substrate and a crystal supported by the package substrate,the crystal being disposed between the die and the package substrate,and the die including the low noise amplifier and the multi-mode poweramplifier.
 5. A front end system comprising: a low noise amplifier in areceive path of the front end system, the low noise amplifier includinga first inductor, an amplification circuit, and a second inductormagnetically coupled to the first inductor to provide negative feedbackto linearize the low noise amplifier; and a multi-mode power amplifiercircuit in a transmit path of the front end system, the multi-mode poweramplifier circuit including a stacked output stage including atransistor stack of two or more transistors, and the multi-mode poweramplifier circuit including a bias circuit configured to control a biasof at least one transistor of the transistor stack based on a mode ofthe multi-mode power amplifier circuit.
 6. The front end system of claim5 wherein the bias circuit is configured to bias a transistor of thetransistor stack to a linear region of operation in a first mode, and asa switch in a second mode.
 7. The front end system of claim 6 whereinthe bias circuit is configured to bias the transistor in a saturationregion of operation in the second mode.
 8. The front end system of claim6 wherein the second mode is associated with a lower power than thefirst mode.
 9. The front end system of claim 6 wherein the stackedoutput stage is configured to receive a supply voltage having a lowervoltage level in the second mode relative to the first mode.
 10. Thefront end system of claim 5 wherein the stacked output stage is operablein at least three different modes.
 11. The front end system of claim 5wherein the transistor stack includes at least three transistors inseries.
 12. The front end system of claim 5 wherein the amplificationcircuit is configured to receive a radio frequency signal by way of thefirst inductor.
 13. The front end system of claim 12 wherein the lownoise amplifier includes an input matching circuit including the firstinductor and a series inductor having a first end configured to receivethe radio frequency signal and a second end electrically coupled to thefirst inductor.
 14. The front end system of claim 13 wherein thematching circuit further includes a direct current blocking capacitorconfigured to provide the radio frequency signal to the series inductor.15. The front end system of claim 5 wherein the second inductor is adegeneration inductor.
 16. The front end system of claim 5 furthercomprising a radio frequency switch coupled to the low noise amplifierand the multi-mode power amplifier circuit.
 17. The front end system ofclaim 16 wherein the radio frequency switch is configured toelectrically couple an antenna port to the transmit path in a firststate and to electrically couple the antenna port to the receive path ina second state.
 18. A wireless communication device comprising: a lownoise amplifier in a receive path of a front end system, the low noiseamplifier including a first inductor, an amplification circuit, and asecond inductor magnetically coupled to the first inductor to providenegative feedback to linearize the low noise amplifier; a multi-modepower amplifier circuit in a transmit path of the front end system, themulti-mode power amplifier circuit including a stacked output stageincluding a transistor stack of two or more transistors, and themulti-mode power amplifier circuit including a bias circuit configuredto control a bias of at least one transistor of the transistor stackbased on a mode of the multi-mode power amplifier circuit; an antenna;and a radio frequency switch configured to electrically couple theantenna to the transmit path in a first state and to electrically couplethe antenna to the receive path in a second state.
 19. The wirelesscommunication device of claim 18 wherein the low noise amplifier and themulti-mode power amplifier are embodied on a singlesemiconductor-on-insulator die.
 20. The wireless communication device ofclaim 18 wherein the multi-mode power amplifier circuit is configured tooutput a wireless local area network signal for transmission via theantenna.